Aviation Boatswain’s Mate E 3 & 2

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NAVEDTRA 12360-A

Naval Education and February 1995 Training Manual

Training Command 0502-LP-480-5500 (TRAMAN)

Aviation BoatswainsMate E 3 & 2

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

The public may request copies of this document by followingthe purchasing instruction on the inside cover.


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Although the words he, him, and hisare used sparingly in this manual to enhancecommunication, they are not intended to begender driven nor to affront or discriminateagainst anyone reading this text.

D I STR I B UTI O N STATEM EN T A: App r oved f or pu b l i c r e l ea se ; d i s t r i bu t i on i s u n l i m i t ed .

T h e p u b l i c ma y r e q u e s t c o p i e s o f t h i s d o c u me n t b y w r i t i n g t o S u p e r i n t e n d e n t o f D o c u me n t s G o v e r n me n t P r i n t i n gOff ice , Washington, DC 20402-0001 or to the ASO/NPFD, At tent ion Cash Sales (Code 1013) , 5801 Tabor Avenue,Ph i ladelph ia , P A 19120-5099.


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AVIATION BOATSWAINSMATE E 3 & 2

1995 Ed i t io n Prep a red b yABE CS N . G. McClur e


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P R E F A C E

This training manual (TRAMAN), Aviation Boatswain s Ma te E 3 & 2,(Launching and Recovery Equipment), NAVEDTRA 12360-A, and thenonresident training course (NRTC), NAVEDTRA 82360-A, form self-studyunits that are designed for individual study rather than formal classroominstruction. The training manual (TRAMAN) alone can be used for formal

or informal instruction. This TRAMAN is intended to prepare personnel toserve as Aviation Boatswains Mates, and its subject matter relates directly tothe occupation standards (OCCSTDS).

The r evision of this t ra ining ma nu al includes th e deletion of referencesto obsolete equipment, organizational structures, and aircraft carriers nolonger in serv ice . Throughout t h is manua l , the text h as been rev ised tofacili ta te easier reading and better understanding of the mater ial . Manyreferences and illust ra tions are u pdat ed in t his revision of ABE 3&2.

When you are assigned the duties of an Aviation Boatswains Mate, youwill be expected to know and understand the information in this manual. The

success of the Navy depends in part on your ability and the manner in whichyou perform your assigned duties.

The NRTC designed for use with this manual must be ordered inaccordance with instruction in the List of Training Manuals and NonresidentTrain ing Courses, NAVEDTRA 12061. The NRTC consists of individualassignmen ts, each cont aining a series of questions ba sed on inform at ion inth e TRAMAN. They are intended t o lead stu dents t hrough st udy of th eTRAMAN, thus satisfying a requirement for advancement qualification.

This TRAMAN and associated NRTC were prepared by the NavalEducation and Training Program Management Support Activity, Pensacola,

Florida, for the Chief of Naval Education and Training.

1995 Edition

S t o c k O r d e r i n g N o .

0502-LP-480-5500

Published byNAVAL EDUCATION AND TRAINING PROGRAM

MANAGEMENT SUPPORT ACTIVITY

UNITED STATESGOVERNMENT PRINTING OFFICE

WASHINGTON, D.C.; 1995

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THE UNITED STATES NAVY

GUARDIAN OF OUR COUNTRY

The United States Navy is responsible for maintaining control of the sea

and is a ready force on watch at home and overseas, capable of strongaction to preserve the peace or of instant offensive action to win in war.

It is upon the maintenance of this control that our countrys glorious futuredepends; the United States Navy exists to make i t so.

WE SERVE WITH HONOR

Tradition, valor, and victory are the Navys heritage from the past. Tothese may be added dedication, discipline, and vigilance as the watchwordsof the present and the future.

At home or on distant stations we serve with pride, confident in therespect of our country, our shipmates, and our families.

Our responsibilities sober us; our adversities strengthen us.

Service to God and Country is our special privilege. We serve with honor.

THE F UTURE OF TH E NAVY

The Navy will always employ new weapons, new techniques, and greaterpower to protect and defend the United States on the sea, under the sea,and in the air .

Now and in the future, control of the sea gives the United States hergreatest advantage for the maintenance of peace and for victory in war.

Mobility, surprise, dispersal, and offensive power are the keynotes of thenew Navy. The roots of the Navy lie in a strong belief in the future, incontinued dedication to our tasks, and in reflection on our heritage fromthe past.

Never have our opportunities and our responsibilities been greater.

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CONTENTS

CHAPTER PAGE

1. Comm on Maint ena nce Tools a nd Their Uses . . . . . . . . . . . . . 1-1

2. Measuring Tools and Techniques.. . . . . . . . . . . . . . . . . . 2-1

3. Mk 7 Aircraft Recovery Equipment and BarricadeSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

4. Steam Catapults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

5. Associated Launching Equipment . . . . . . . . . . . . . . . . . . . . . 5-1

6. The Aircraft Launch and Recovery EquipmentMaintenance Program (ALREMP) . . . . . . . . . . . . . . . . . . . . 6-1

APPENDIX

I. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. AI-1

II. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. AII-1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. INDEX-1

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CHAPTER 1

COMMON MAINTENANCE TOOLS ANDTHEIR USES

Tools are designed to make a job easier and

enable you to work more efflciently. If they are notproperly used and cared for, their advantages are lostto you.

Regardless of the type of work to be done, youmust have, choose, and use the correct tools in orderto do your work quickly, accur at ely, an d sa fely.Without the proper tools and the knowledge of how touse them, you waste time, reduce your efficiency, andmay even injure yourself.

This chapter explains the specific purposes, correct

use, and proper care of the more common tools youwill encounter as an ABE. Also discussed briefly areother aids to maintenance, such as blueprints andschematics.

Upon completing this chapter, you should be ableto do the following:

Identify, select, use, maintain, and inventorythe tools required to perform maintenance oncatapults and arresting gear.

Explain the various methods of conductinginventories and maintaining tools in supportof the tool control program.

Recognize, describe, and interpret tool safetyprocedures.

Recognize, describe, and interpret the varioustypes - of blueprints, electrical prints, pipingprints, and aperture cards used to maintainand repair catapults and arrest ing gear.

Use and Care of Ha nd Tools an d Measu ringTools, NAVEDTRA 12085, is an excellent referenceto use while reading and studying this chapter.

TOOL WORK HABITS

A place for everything and everything in itsplace is just good common sense. You cant do anefficient repa ir job if you h ave t o stop a nd look

around for each tool you need. The following rules

will make your job easier and safer.

KEEP EACH TOOL IN ITS PROPERSTOWAGE PLACEAll V-2 divisions haveincorporated a Tool Control Program as directed bythe Aircraft Launch and Recovery EquipmentMaintenance Program (ALREMP).

The Tool Control Program is based on the conceptof a family of specialized toolboxes and pouchesconfigured for instant inventory before and after eachmaintenance action. The content and configuration of

each container is tailored to the task, work center, andequipment maintained. Work center containers areassigned to and maintained within a work center.Other boxes and specialized tools are checked outfrom the tool control center (tool room).

K E E P Y O U R T O O L S I N G O O DCONDITIONProtect them from rust, nicks, burrs,and breakage.

K E E P Y O U R T O O L A L L O W A N C ECOMPLETE When you are issued a toolbox, eachtool should be placed in it when not in use. When thetoolbox is not actually at the work site, it should belocked and stored in a designated area.

NOTE

An inventory list is kept in every toolboxto be checked before and after each job ormaintenance action, to ensure that all tools areavailable to do your work, and to ensure thatthey are accounted for after you have

completed your work.USE EACH TOOL ONLY FOR THE JOB IT

WAS DESIGNED TO DO Each particular type oftool has a specific purpose. If you use the wrong toolwhen performing maintenance or repairs, you maycause damage to the equipment youre working on ordamage the tool itself. Remember, improper use of

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tools results in improper maintenance. Improper maintenance results in damage to equipment and possibleinjury or death to you or others.

SAFE MAINTENANCE PRACTICESAlwaysavoid placing t ools on or a bove ma chinery or a nelectrical apparatus. Never leave tools unattendedwhere machinery or aircraft engines are running.

NEVER USE DAMAGED TOOLS A batteredscrewdriver may slip and spoil the screw slot, damageother parts, or cause painful injury. A gauge strainedout of shape wil l result in inaccurate measurements.

Remember, the efficiency of craftsmen and thetools they use are determined to a great extent by theway th ey keep their t ools. Likewise, they arefrequently judged by the manner in which they handleand care for them. Anyone watching skilledcraftsmen at work notices the care and precision with

which they use the tools of their trade.

The care of hand tools should follow the samepattern as for personal articles; that is, always keephan d t ools clean an d free from dirt, grease, an dforeign matter. After use, return tools promptly totheir proper place in the toolbox. Improve your ownefficiency by organizing your tools so that those usedmost frequently can be reached easily without diggingth rough th e entire cont ents of the box. Avoidaccumulating unnecessary junk.

STRIKING TOOLS

Hammers, mallets, and sledges are used to applya striking force. The tool you select (fig. 1-1) willdepend upon the intended application.

HAMMERS

A toolkit for nearly every rating in the Navywould not be complete without at least one hammer.In most cases, two or three are included, since theyare designated according to weight (without the

han dle) and style or sh ape. The shape will varyaccording to the intended work.

M a c h i n i s t s H a m m e r s

Machinists hammers are mostly used bywho work with metal or around machinery.

peopleThese

hammers are distinguished from carpenter hammers bya variable-shaped peen, rather than a claw, at the

Figure 1-1 .- H am m er s m a l l e t s , and s l edges .

opposite end of the face (fig. 1-1). The ball-peenhammer is probably most familiar to you.

The ball-peen ham mer, as i ts n am e implies, has aball that is smaller in diameter than the face. It istherefore useful for striking areas that are too small

for the face to enter.

Ball-peen hammers are made in different weights,usu ally 4, 6, 8, and 12 oun ces an d 1, 1 1/2, and 2pounds. For most work a 1 1/2 pound and a 12-ouncehammer will suffice. However, a 4- or 6-inchhammer will often be used for light work such astapping a punch to cut gaskets out of sheet gasketmaterial.

Machinists ham mers may be furt her divided intohard-face and soft-face classifications. The hard-faced

hammer is made of forged tool steel, while thesoft-faced hammers have a head made of brass, lead,or a tightly rolled strip of rawhide. Plastic-facedhammers or solid plastic hammers with a lead core foradded weight are becoming increasingly popular.

Soft-faced h am mers (fig. 1-1) should be usedwhen there is danger of damaging the surface of thework, as when poundind on a machined surface.

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Most soft-faced hammers have heads that can bereplaced as the need arises. Lead-faced hammers, forinsta nce, quickly become bat tered a nd m ust bereplaced, but have the advantage of striking a solid,heavy nonrebounding blow that is useful for such jobsas driving shafts into or out of tight holes. If asoft-faced hammer is not available, the surface to behammered may be protected by covering it with apiece of soft brass, copper, or hard wood.

U s in g H a m m e r s

Simple as the hammer is, there is a right and awrong way of using it. (See fig. 1-2.) The mostcommon fault is holding the handle too close to thehead. This is known a s choking the h amm er, andreduces the force of the blow. It also makes it harderto hold the head in an upright position. Except forlight blows, hold the handle close to the end toincrease leverage and produce a more effective blow.Hold the handle with the fingers underneath and the

thumb along side or on top of the handle. The thumbshould rest on the handle and never overlap thefingers. Try to hit the object with the full force of thehammer. Hold the hammer a t such an angle tha t theface of the hammer and the surface of the object beinghit will be parallel. This distributes the force of theblow over the full face and prevents damage to boththe surface being struck and the face of the hammer.

MALLETS AND SLEDGE S

The mallet is a short-handled tool used to drivewooden-handled chisels, gouges, and wooden pins, orto form or sha pe sheet m etal where har d-facedhammers would mar or damage the finished work.Mallet heads are made from a soft material , usuallywood, rawhide, or r ubber . F or exa mple, arubber-faced mallet is used for knocking out dents inan automobile. It is cylindrically shaped with two flatdriving faces that are reinforced with iron bands. (Seefig. 1-1.) Never use a mallet to drive nails, screws, orany other object that can damage the face of themallet .

The sledge is a steel-headed, heavy-duty drivingtool tha t can be used for a nu mber of pur poses.Short-handled sledges are used to drive driftpins, andlarge nails, and to strike cold chisels and smallhand-held rock drills. Long-handled sledges are usedto break rock and concrete, to drive spikes or stakes,and to strike rock drills and chisels.

ma de of a

Figure 1-2 .- S t r i k i ng a s u r f ace .

The h ead of a sledge is generallyhigh-carbon steel and may weigh from 2 to 16pounds. The shape of the head will vary according tothe job for which the sledge is designed.

MAINTENANCE OF STRIKINGTOOLS

Hammers, sledges, or mallets should be cleanedand repaired if necessary before they are stored.Before using them, make sure the faces are free fromoil or other material that would cause the tool toglance off na ils, spikes, or sta kes. The h eads shouldbe dressed to remove any battered edges.

Never leave a wooden or rawhide mallet in thesun, as i t will dry out a nd m ay cause th e head tocrack. A light film of oil should be left on the malletto maintain a little moisture in the head.

The hammer handle should always be t ight in thehead. If it is loose, the head may fly off and cause aninjury.

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SAFETY PRECAUTIONS

Hammers are dangerous tools when usedcarelessly and without consideration. Practice willhelp you learn to use a hammer properly.

Some important things to remember when usinga hammer or mallet follow:

Do not use a hammer handle for bumpingpart s in assembly, and never use i t as a pry bar. Suchabuses will cause the handle to split, and a splithandle can produce bad cuts or pinches. When ahandle splits or cracks, do not try to repair it bybinding with string, wire, or tape. Replace it .

Make sure the handle fits tightly on the head. Do not strike a hardened steel surface with a

steel ha mm er. Sma ll pieces of steel ma y break offand injure someone in the eye or damage the work.

However, it is permissible to strike a punch or chiseldirectly with a ball-peen hammer, because the steel inthe heads of punches and chisels is slightly softer thanthat of the hammerhead.

WRENCHES

A wrench is a basic tool that is used to exert atwisting force on bolt heads, n ut s, studs, a nd pipes.The special wrenches designed to do certain jobs are,in most cases, variations of the ba sic wrenches th atare described in this section.

The best wrenches are made of chrome vanadiumsteel. Wrenches made of this material are lightweight

Figure 1-3 .- Op e n - e n d wr e n c h e s .

and almost unbreakable. This is an expensivematerial, however, so the most common wrenchesfound in the Navy are made of forged carbon steel ormolybdenum steel. These latter materials make goodwrenches, but they are generally built a little heavierand bulkier to achieve the same degree of strength aschrome vanadium steel.

The size of any wrench used on bolt heads or nuts

is determined by the size of the opening between thejaws of the wr ench. The opening of a wrench ismanufactured slightly larger than the bolt head or nutth at it is designed t o fit. Hex-nu ts (six-sided) an dother types of nut or bolt heads are measured acrossopposite flats (fig. 1-3). A wrench that is designed tofit a 3/8-inch nut or bolt usually has a clearance offrom 5 to 8 thousandths of an inch. This clearanceallows the wrench to slide on and off the nut or boltwith a minimum of play. If the wrench is too large,the points of the nut or bolt head will be rounded anddestroyed.

There are many types of wrenches. Each type isdesigned for a specific use. Lets discuss some ofthem.

OPEN-END WRENCHES

Solid, nonadjustable wr enches with openings inone or both ends are called open-end wrenches. (Seefig. 1-3.) Usually they come in sets of from 6 to 10wrenches, with sizes ran ging from 5/16 to 1 inch.Wrenches with small openings are usually shorter than

wrenches with large openings. This proportions t helever advantage of the wrench to the bolt or stud andhelps prevent wrench breakage or damage to the boltor stud. One exception exists.

Hydraulic piping installations for catapult andarresting gear are often in close spaces. Duringcertain phases of hydraulic maintenance it may beimpossible to swing an ordinary wrench because of itslength. Ordinary wrenches that are normally availableincrease in length as their size increases. Thus, whena large-size wrench is n eeded, the length of th e

wrench sometimes prevents its use, due to the spaceavailable to swing the wrench. The Bonney wrench,shown in figure 1-4, is an open-end wrench that maybe used to great advantage because of its thicknessand short length. This wrench is normally procuredin the larger sizes, although it is available in a rangeof sizes to fit most hydraulic fittings.

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Figure 1-4 .- B onney w r enches .

Open-end wrenches may have their jaws parallelto the ha ndle or a t an gles anywhere up t o 90 degrees.The average angle is 15 degrees (fig. 1-3). Thisangular displacement variation permits selection of awrench suited for places where there is room to makeonly a part of a complete turn of a nut or bolt. If thewrench is turned over after the first swing, it will fiton the same flats and turn the nut farther. After twoswings on the wrench, the nut is turned far en ough sothat a new set of flats are in position for the wrench,as shown in figure 1-5.

Handles are usually straight , but may be curved.Those with curved handles are called S-wrenches.Other open-end wrenches may have offset handles.This al lows the head to reach nut or bolt heads thatare sunk below the surface.

BOX WRENCHES

Box wrenches (fig. 1-6) are safer than open-endwrenches since there is less likelihood they will slipoff the work. They completely surround, or box, anut or bolt head.

The most frequently used box wrench has 12points or notches ar ran ged in a circle in the head a ndcan be used with a minimum swing angle of 30degrees. Six- and eight-point wrenches are used forheavy duty; twelve-point for medium, and sixteen forlight-duty only.

One advantage of the 12-point construction is thethin wall . It is more suitable for turning nuts that arehard to get at with an open-end wrench. Anotheradvantage is that the wrench will operate betweenobstructions where the space for handle swing islimited. A very short swing of the handle will turn

the nut far enough to allow the wrench to be liftedand the next set of points fitted to the comers of thenut .

One disadvantage of the box-end wrench is thetime loss that occurs whenever a craftsman has to liftthe wrench off and place it back on the nut in anotherposition when th ere is insu fficient cleara nce to spinthe wrench in a full circle.

COMBINATION WRENCH

After a tight nut is broken loose, it can beunscrewed much more quickly with an open-endwrench than with a box-wrench. A combinationbox-open end wrench (fig. 1-7) comes in handy in asituation of the type. You can use the box-end forbreaking nuts loose or for snugging them down, andthe open-end for faster turning.

The box-end portion of the wrench can be

designed with a n offset in th e ha ndle. Notice infigure 1-7 how the 15-degree offset allows clearanceover nearby parts.

The correct use of open-end and box-endwrenches can be summed up in a few simple rules,most important of which is to be sure tha t t he wrenchproperly fits the nut or bolt head.

When you have to pull hard on the wrench, as inloosening a t ight nu t , mak e sure t he wrench is seatedsquarely on t he flats of the n ut .

Pull on the wrench DO NOT PUSH. Pushing awrench is a good way to skin your knu ckles if th ewrench slips or the nut breaks loose unexpectedly. Ifit is impossible to pull the wrench and you must push,do it with the palm of your hand and hold your palmopen.

Only actual practice will tell you if you are usingthe right amount of force on the wrench. The bestway to t ighten a n ut is to turn i t unti l the wrench hasa firm, solid feel. This will turn the nut to propert ightness without str ipping th e th reads or twist ing offthe bolt. This feel is developed by experiencealone. Practice until you have mastered the feel.

SO C K E T W R E N C H

The socket wrench iswrenches in the toolbox.

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one of the most versatileBasically, it consists of a


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Figure 1-5 . -Us e o f o p e n - e n d wr e n c h .

handle and a socket-type wrench that can be to accommodate a bolt protruding through a nut, hasattachedto the handle. a h exagonal h ead, and is used like a screwdriver. It

is supplied in sm all sizes only an d is us eful forThe Spint ite wren ch, shown in figure 1-8, is a assembly and electrical work. When used for the

special type of socket wrench. It has a hollow shaft latter purpose, it must have an insulated handle.

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F i g u re 1 -6 .-1 2 -p o i n t b o x -en d wren ch .

F i g u re 1 -9 .-1 2 -p o i n t so ck e t s .

S o c k e t s

A socket (fig. 1-9) has a squa re opening cut inone end to fit a square drive lug on a detachable

Figure 1-7 . -O f f s e t com bi na t i on w r ench . handle. In the other end of the socket is a 6-point or12-point opening, very much like the opening in the

A complete socket wrench set consists of several box-end wrench. The 12-point socket needs to be

types of handles along with bar extensions, adapters, swung only half as far as the 6-point socket before it

and a variety of sockets (fig. 1-8). has to be lifted and fitted on the nut for a new grip.It can therefore be used in closer quarters where thereis less room to move the handle. (A ratchet handleeliminates the necessity of lifting the socketrefi t t ing i t on the nut again and again.)

and

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Figure 1-8 . -Socke t s e t com ponen t s .


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Sockets are classified by size according to twofactors. One is the size of the square opening, whichfits on the square drive lug of the handle. This size isknown as the drive size. The other is the size of theopening in the opposite end, which fits the nut or bolt.The standard toolbox can be outfitted with socketshaving 1/4-, 3/8-, and 1/2-inch-square drive lugs.Larger sets are usually available in the tool room fortemporary checkout. The openings that fit onto the

bolt or nut are usually graduated in 1/16-inch sizes.Sockets are also made in deep lengths to fit overspark plugs and long bolt ends.

So ck e t Han d le s

There are four types of handles used with thesesockets. (See fig. 1-8.) Each type has specialadvantages, and the experienced worker chooses theone best suit ed for the job at han d. The squaredriving lug on th e socket wren ch h andles ha s aspring-loaded ball that fits into a recess in the socketreceptacle. This mated ball-recess feature keeps thesocket engaged with the drive lug during normalusage. A slight pull on the socket, however,disassembles the connection.

R A T C H E T . The ratchet handle has a reversinglever that operates a pawl (or dog) inside the head ofthe tool. Pulling the handle in one direction causesthe pawl to engage the ratchet teeth and turn thesocket. Moving the handle in the opposite directioncauses the pawl to slide over the teeth, permitting thehandle to back up without moving the socket. Thisallows rapid turning of the nut or bolt after eachpart ial turn of the ha ndle. With th e reversing lever inone position, the handle can be used for tightening.In the other position, it can be used for loosening.

HINGED HANDLE. The h inged ha ndle is alsovery convenient. To loosen tight nuts, swing thehandle at right angles to the socket. This gives thegreatest possible leverage. After loosening the nut tothe point where i t turns easi ly, move the handle intothe vertical position and then turn the handle with the

fingers.

SLIDING T-BAR HANDLE. When you areusing the sliding bar or T-handle, the head can bepositioned anywhere along the sliding bar. Select theposition that is needed for the job at hand.

S P E E D H A N DL E . The speed handle is workedlike the woodworkers brace. After the nuts are first

loosened with the sliding bar handle or the ratchethandle, the speed handle can be used to remove thenuts more quickly. In many instances the speedhandle is not strong enough to be used for breakingloose or tightening the nut. The speed socket wrenchshould be used carefully to avoid damaging the nutthreads.

A c c e s s o r i e s

Several accessory items complete the socketwrench set. Extension bars of different lengths aremade to extend the distance from the socket to thehandle. A universal joint allows the nut to be turnedwith the wrench handle at an angle. Universal socketsare also available. The use of universal joints, barextensions, and universal sockets in combination withappropriate handles makes it possible to form avariety of tools that will reach otherwise inaccessiblenuts and bolts.

Another accessory item is an adapter, whichallows you to use a handle having one size of driveand a socket having a different size drive. Forexample, a 3/8- by 1/4-inch adapter makes it possibleto tu rn all 1/4-inch-squa re drive sockets wit h a ny3/8-inch-square drive handle.

TORQUE WRENCHES

There are times when, for engineering reasons, adefinite force must be applied to a nut or bolt head.In such cases a torque wrench must be used. Forexample, equal force must be applied to all the headbolts of an engine. Otherwise, one bolt may bear thebrunt of the force of internal combustion andultimately cause engine failure.

The three most commonly used torque wrenchesare the deflecting beam, dial indicating, andmicrometer set t ing types (fig. 1-10). When using thedeflecting beam and the dial indicating torquewrenches, read the torque visually on a dial or scalemounted on the handle of the wrench.

To use the micrometer setting type, unlock thegrip and adjust the handle to the desired setting on themicrometer-type scale, then relock the grip. Installthe required socket or adapter to the square drive ofthe handle. Place the wrench assembly on the nut orbolt and pull in a clockwise direction with a smooth,

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Figure 1-10.- Tor que w r enches .

steady motion. (A fast or jerky motion will result in

an improperly torqued unit.) When the torque appliedreaches the torque value, which is indicated on thehan dle set t ing, a signal mechanism will aut oma ticallyissue an audible click, and the handle will release orbreak, and move freely for a short distance. Therelease and free travel is easily felt, so there is nodoubt about when the torquing process is complete.

Manufacturers and technical manuals generallyspecify the amount of torque to the applied. Toassure getting the correct amount of torque on thefasteners, it is important that the wrench be used

properly according to manufacturers instructions.

Use the torque wrench that will read aboutmid-range for the amount of torque to be applied. BESURE THE TORQUE WRENCH HAS BEENCALIBRATED BEFORE YOU USE IT. Remember,too, that the accuracy of torque-measuring depends alot on how the threads are cut and the cleanliness ofthe t hreads. Make sure you inspect a nd clean t hethreads. If the manufacturer specifies a threadlubricant , it m ust be used to obtain th e most accura tetorque reading. When using the deflecting beam or

dial indicating wrenches, hold the torque at the desiredvalue unti l the r eading is steady.

Torque wrenches are delicate and expensive tools.The following precautions should be observed whenusing them:

1. When using the micrometer setting type, do

not move the setting handle below the lowest torquesetting. However, it should be placed at its lowestsetting before it is returned to storage.

2. Do not use the torque wrench to apply greateramount s of torque tha n i ts r ated capacity.

3. Do not use the torque wrench to loosen boltsthat have been previously tightened.

4. Do not dr op t he wren ch. If a t orque wrenchis dropped, its accuracy will be affected.

5. Do not a pply a t orque wrench to a nu t t hathas been t ightened. Back off the nut one turn with anontorque wrench and ret ighten to the correct torquewith the indicating torque wrench.

6. Calibration intervals have been established forall torque tools used in the Navy. When a tool iscalibrated by a qualified calibration activity at ashipyard, tender, or repair ship, a label showing thenext calibration due dat e is att ached to the ha ndle.This date should be checked before a torque tool is

used to ensure that it is not overdue for calibration.

ADJUSTABLE WRENCHES

A handy all-round wrench th at is generallyincluded in every toolbox is the adjustable open-endwrench. This wrench is not intended to take the placeof the regular solid open-end wrench. Additionally, it

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is not built for use on extremely hard-to-turn items.Its usefulness is achieved by being capable of fittingodd-sized nuts. This flexibility is achieved althoughone jaw of the adjustable open-end wrench is fixed,becau se th e other jaw is m oved along a slide by athumbscrew adjustment (fig. 1-11). By turning thethumbscrew, you can adjust the jaw opening to fitvarious sizes of nuts.

Adjustable wrenches are available in varying sizes,normally ranging from 4 to 24 inches in length. Thesize of the wrench selected for a particular job isdependent upon the size of the nut or bolt head towhich the wrench is to be applied.

Adjustable wrenches are often called knucklebusters, because mechanics frequently suffer theseconsequences as a result of improper usage of thesetools. To avoid accidents, follow four simple steps.First, choose a wrench of the correct size; that is, donot pick a large 12-inch wrench and adjust the jaw for

use on a 3/8-inch nut. This could result in a brokenbolt and a bloody hand. Second, be sure the jaws ofthe correct-size wrench are adjusted to fit snugly onthe nut. Third, position the wrench around the nutuntil the nut is all the way into the throat of the jaws.If the wrench is not used in this manner, the result isapt to be as bloody as before. Fourth, pull the handletoward the side having the adjustable jaw (fig. 1-12).

Figure 1-12.-P r o p e r p r o c e d u r e f o r u s i n g a d j u s t a b l ew r e n c h e s .

This will prevent the adjustable jaw from springingopen and slipping off the nut. If the location of thework will not allow for all four steps to be followedwhen u sing an a djusta ble wrench, then select a nothertype of wrench for the job.

Pip e W r en ch ( S t i l l so n )

In rotating or holding round work, an adjustablepipe wrench (Stillson) may be used (fig. 1-13). Themovable jaw on a pipe wrench is pivoted to permit agripping action on the work. This tool must be usedwith discret ion, as the jaws are serrated and alwaysmake marks on the work unless adequate precautionsare observed. The jaws should be adjusted so the biteon the work will be taken at about the center of the

jaws.

C h a i n P i p e W r e n c h

A different typelarge sizes of pipe,

of pipe wrench, used mostly onis the chain pipe wrench (fig.

1-14). This tool works in one direction only, but canbe backed part ly around the work a nd a fresh h oldtaken without freeing the chain. To reverse theoperation, the grip is taken on the opposite side of thehead. The head is double sided and can be reversedwhen the teeth on one side are worn out .

Figure 1-13.-A d j us t ab l e p i pe w r ench .Figure 1-11.- A d j us t ab l e w r enches .

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F i g u re 1 -1 4 .-C h a i n p i p e w r e n c h .

S t r a p W r e n c h

The strap wrench (fig. 1-15) is similar to the chainpipe wrench but uses a heavy web strap in place of

the chain. This wrench is used for turning pipe orcylinders where you do not want to mar the surface ofthe work. To use this wrench, the webbed strap isplaced around t he pipe and pa ssed through th e slot inth e meta l body of the wrench. The stra p is th enpulled up tight; and as the mechanic turns the wrenchin the desired direction, the webbed strap tightensfuther around the pipe. This gripping action causesthe pipe to turn.

SPANNER WRENCHES

Many special nuts a re ma de with notches cut intotheir outer edge. For these nuts a hook spanner (fig.1-16) is required. This wrench has a curved arm witha lug or hook on the end. This lug fits into one of thenotches of the nut, and the handle is turned to loosenor t ighten the nut . This spanner may be made for just

Figure 1-16.- G e n e r a l - p u r p o s e s p a n n e r w r e n c h e s .

one particular size of notched nut, or it may have ahinged arm to adjust it to a range of sizes.

Another type of spanner is the pin spanner. Pinspan ner s ha ve a pin in pla ce of a hook. This pin fitsinto a hole in the outer pa rt of the nut .

Face pin spanners are designed so that the pins fitinto holes in th e face of th e nu t (fig. 1-16).

When you use a spanner wrench, you must makesure the pins, lugs, or hooks make firm contact withthe nut while the turning force is transferred from thewrench to the nut. If this is not done, damage willresult to tools or equipment or injury to personnel.

SETSCREW WRENCHES(ALLEN AND BRISTOL)

In some places it is desirable to use recessedheads on setscrews and capscrews. One type of screw(Allen) is used extensively on office machines and in

Figure 1 -15 .-S t r a p w r e n c h .

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machine shops. The other type (Bristol) is usedinfrequently.

Recessed-head screws usually have a hex-shaped(six-sided) recess. To remove or tighten this type ofscrew requires a special wrench that will fit in therecess. This wrench is called an Allen-type wrench.Allen wrenches are made from hexagonal L-shapedbars of tool steel (fig. 1-17). They generally range in

size up to 3/4 inch. When u sing th e Allen-typewrench, make sure you use the correct size to preventrounding or spreading the head of the screw. A snugfit within the recessed head of the screw is anindication that you have the correct size.

The Bristol wrench is made from round stock. Itis also L-shaped, but one end is fluted to fit the flutesor little splines in the Bristol setscrew (fig. 1-17).

SA FE T Y R U L E S F O R W R E N C H E S

There are a few basic rules that you should keepin mind when using wrenches. They are as follows:

Always use a wrench that fits the nutproperly.

Keep wrenches clean and free from oil.Otherwise they may slip, resulting in possible seriousinjury to you or damage to the work.

Do not increa se th e levera ge of a wrench byplacing a pipe over the handle. Increased leverage

may damage the wrench or the work.

Provide some sort of kit or case for allwrenches. Return them to the case at the completionof each job. This saves time and tr ouble and a idsselection of tools for the next job. Most important, iteliminates the possibility of leaving them where theycan cause injury to personnel or damage to equipment.

Determine which way a nut should be turnedbefore t rying to loosen it. Most nu ts are t urn edcounterclockwise for removal. This may seemobvious, but even experienced people have beenobserved straining at the wrench in the tighteningdirection when they wanted to loosen the nut.

Learn to select your wrenches to fit the typeof work you are doing. If you are not familiar withthese wrenches, make a rra ngements to visit a shopthat has most of them, and get acquainted.

Figure 1-17.-A l l en - and B r i s t o l - t ype w r enches .

METAL-CUTTING TOOLS

Many types of metal-cutting tools are used byskilled mechanics of all ratings. As you becomebetter acquainted with the ABE rating, you willprobably discover many tools that you use for cuttingmetal that are not described in this text . In this text ,only the basic hand metal-cutting tools will beconsidered.

SNIPS AND SHEARS

Snips and shears are used for cutt ing sheet metaland steel of various thicknesses and shapes.Normally, the heavier or thicker materials are cut byshears.

One of the handiest tools for cutting light (up to1/16-inch thick) sheet metal is the hand snip (tipsnips). The STRAIGHT HAND SNIPS, shown infigure 1-18, have b lades tha t are s t ra ight a nd cut t ing

edges that are sharpened to an 85-degree angle. Snipslike this can be obtained in different sizes, rangingfrom th e sm all, 6-inch, to th e lar ge, 14-inch, snip. Tinsnips will also work on slightly heavier gauges of softmetals, such as aluminum alloys.

Snips will not remove any metal when a cut ismade. There is danger, though, of causing minutemetal fractures along the edges of the metal during theshearing process. For this reason, it is better to cut

just outside the layout line. This procedure will allowyou to dress the cutting edge while keeping materialwithin required dimensions.

Cutt ing extremely heavy gauge metal a lwayspresents the possibility of springing the blades. Oncethe blades are sprung, hand snips are useless. When

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F i g u re 1 -1 8 .-M et a l sn i p s .

cutting heavy material, use the rear portion of theblades. This procedure not only avoids the possibilityof springing th e blades but also gives you greatercutting leverage.

Many snips have small serrations (notches) on thecutting edges of the blades. These serrations tend toprevent the snips from slipping backwards when a cutis being made. Although this feature does make theactual cutt ing easier, i t mars the edges of the metalslightly. You can remove these small cutting marksif you allow proper clearance for dressing the metal tosize. There are many other types of hand snips usedfor special jobs, but the snips discussed here can beused for almost any common type of work.

C u t t i n g S h e e t M e t a l w i t h S n i p s

It is hard to cut circles or small arcs with straightsnips. There are snips especially designed for circularcutting. They are called CIRCLE SNIPS,HAWKS-BILL SNIPS, TROJAN SNIPS, andAVIATION SNIPS (fig. 1-18).

To cut large holes in the lighter gauges of sheetmetal , start the cut by punching or otherwise makinga hole in the center of the area to be cut out. With anaviation snips, or some other narrow-bladed snips,make a spiral cut from the starting hole out toward thescribed circle, as shown in figure 1-19, and continuecutt ing unti l th e scrap fal ls a way.

Figure 1-19.- C u t t i ng an i n s i de ho l e w i t h s n i ps .

To cut a disk in the lighter gauges of sheet metal,use a combination snips or a straight-blade snips, asshown in figure 1-20. First , cut away any surplusmaterial outside the scribed circle, leaving only anarrow piece to be removed by the final cut. Makethe final cut just outside the layout line. This will

perm it you t o see th e scribed line while you a recutting and will cause the scrap to curl up below theblade of the snips, where it will be out of the waywhile the complete cut is being made.

To make str aight cuts, place the sheet m etal on abench with the marked guideline over the edge of thebench and hold the sheet down with one hand. Withthe other h and, hold the snips so that t he flat sides ofthe blades are at right angles to the surface of the

Figure 1-20.-C u t t i ng a d i s k ou t o f s hee t m e t a l .

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work. If the blades are n ot at r ight angles to the sur faceof the work, the edges of the cut will be slightly bentand burred. The bench edge will also act as a guidewhen you are cutting with the snips. The snips willforce the scrap metal down so that it does not interferewith cutt ing. Any of th e ha nd sn ips may be us ed forstraight cuts. When notches are too narrow to be cutout with a pair of snips, make the side cuts with thesnips and cut the base of the notch with a cold chisel.

S a fe t y a n d C a r e

Learn to use snips properly. They should alwaysbe oiled and adjusted to permit ease of cutting and toproduce a sur face that is free from bu rrs. If th eblades bind or if they are t oo far spat, t he snipsshould be adjusted. Remember the following safetytips:

Never use snips as screwdrivers, hammers, orpry bars. They break easi ly.

Do not at tempt to cut heavier materials thanthe snips are designed for. Never use tin snips to cuthardened steel wire or other similar objects. Such usewill dent or nick the cutting edges of the blades.

Never toss snips in a toolbox where thecutting edges can come into contact with other tools.This dulls the cutt ing edges and may even break theblades.

When snips are not in use, han g them onhooks or lay them on an uncrowded shelf or bench.HACKSAWS

Hacksaws are used to cut metal that is too heavyfor snips or boltcutters. Thus metal bar stock can becut readily with hacksaws.

There are two parts to a hacksaw: the frame andthe blade. Common ha cksaws h ave eith er an

adjustable or a solid frame (fig. 1-21). Mosthacksaws found in the Navy are of theadjustable-frame type. Adjustable frames can be madeto hold blades from 8 to 16 inches long, while thosewith solid frames take only the length blade for whichthey are made. This length is the distance betweenthe two pins that hold the blade in place.

Figure 1 -21 .-H a c k s a w s .

Hacksaw blades are made of high-grade tool steel,hardened and tempered. There are two types, theall-hard and the flexible. All-hard blades are hardenedthroughout, whereas only the teeth of the flexibleblades are hardened. Hacksaw blades are about1/2-inch wide, have from 14 to 32 teeth per inch, andare from 8 to 16 inches long. The blades have a holeat each end, which hooks to a pin in the frame. Allhacksaw frames, which hold the blades either parallelor at right angles to the frame, are provided with awingnut or screw to permit tightening or removing theblade.

The SET in a saw refers to how much the teethare pushed out in opposite directions from the sides ofthe blade. The four different kinds of set are theALTERNATE set , DOUBLE ALTERNATE s et,RAKER set, and WAVE set. Three of these areshown in figure 1-22.

The teeth in the alternate set are staggered, one tothe left and one to the right throughout the length ofthe blade. On the double alternate set blade, twoajoining teeth are staggered to the right, two to the

Figure 1 -22 .- S e t o f h a c k s a w - b l a d e t e e t h .

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left, and so on. On the raker set blade, every thirdtooth remains s traight and the other two are setalternately. On the wave (undulated) set blade, shortsections of teeth are bent in opposite directions.

Usin g Hack saws

The hacksaw is often used improperly. Althoughit can be used with limited success by aninexperienced person, a little thought and study givento its proper use will result in faster and better workand in less dulling and breaking of blades.

Good work with a hacksaw depends not only uponthe proper use of the saw but also upon the properselection of the blades for the work to be done.Figure 1-23 will help you select the proper blade touse when sawing metal with a hacksaw. Coarseblades, with fewer teeth per inch, cut faster and areless likely to choke up with chips. However, finer

blades, with more teeth per inch, are necessary whenthin sections are beingmade so that , as eachahead of it will still be

To make the cut,

cut. The selection should betooth starts its cut, the toothcutting.

first install the blade in thehacksaw fram e (fig. 1-24) so the t eeth point awayfrom the handle of the hacksaw. (Hand hacksaws cuton the push stroke.) Tighten the wingnut until theblade is definitely under tension. This helps makestraight cuts.

Figure 1-24.- I n s t a l l i ng a hacks aw b l ade .

Place the material to be cut in a vise. Aminimum of overhang will reduce vibration, give abetter cut, and lengthen the life of the blade. Havethe layout line outside of the vise jaw so that the lineis visible while you work.

The proper method of holding the hacksaw isdepicted in figure 1-25. See how the index finger ofthe right hand, pointed forward, aids in guiding theframe.

When cutting, let your body sway ahead and back

with each stroke. Apply pressure on the forwardstroke, which is t he s tr oke, but n ot on t he retu rnstroke. From 40 to 50 cutting strokes per minute isthe usual speed. Long, slow, steady strokes arepreferred.

Figure 1-23.-S e le c t in g t h e p r o p e r h a c k s a w b l a d e .

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For long cuts, rotate the blade in the frame so thatthe length of the cut is not limited by the depth of theframe. Hold the work with the layout line close to thevise jaws, raising the work in the vise as the sawingproceeds.

To remove a frozen nut with a hacksaw, saw intothe nut, as shown in figure 1-26, starting the bladeclose to the threads on the bolt or stud and parallel toone face of the nut, as shown in view A. Saw parallelto the bolt until the teeth of the blade almost reach thelockwasher. Lockwashers are hard and will ruinhacksaw blades, so do not try to saw them. View Bshows when to stop sawing. Then, with a cold chiseland hammer, remove this one side of the nutcompletely by opening the saw kerf. Pu t a nadjustable wrench across this new flat and the oneopposite, and again try to remove the frozen nut.Since very little original metal remains on this oneside of the nut, the nut will either give or break away

entirely and perm it i ts rem oval.To saw a wide kerf in the head of a cap screw or

machine bolt, fit th e han d ha cksaw fram e with twoblades side by side, and with teeth lined up in thesame direction. With slow, steady strokes, saw theslot approximately one-third the thickness of the headof the cap screw, as shown in figur e 1-27. Such aslot will permit subsequent holding or turning with ascrewdriver when it is impossible, due to closequarters, to use a wrench.

Figu re 1-26.-R e m o v i n g a f r o z e n n u t w i t h a h a c k s a w .

Figure 1-27.-C u t t i n g a w i d e k e r f i n t h e h e a d o f a c a psc rew o r bo l t .

Hack saw Sa f e ty

The main dan ger in using hacksaws is injury toyour hand if the blade breaks. The blade will breakif too much pressure is applied, when the saw istwisted, when the cutting speed is too fast, or whenthe blade becomes loose in the frame. Additionally,if the work is not tight in the vise, it will sometimesslip, twisting the blade enough to break it.

C H I S E L S

Chisels are tools that can be used for chipping orcutting metal. They are made from a good grade oftool steel and have a hardened cutting edge andbeveled head. Chisels are classified according to theshape of their points, and the width of the cuttingedge denotes their size. The most common shapes ofchisels are the flat (cold chisel), cape, round nose, anddiamond point (fig. 1-28).

The type of chisel most commonly used is the flatcold chisel, which serves to cut rivets, split nuts, chipcastings, and cut thin metal sheets. The cape chisel isused for special jobs like cutting keyways, narrowgrooves, and square corners. Round-nose chiselsmake circular grooves and chip inside corners.Finally, the diamond-point is used for cuttingV-grooves and sharp corners.

As with other tools, there is a correct techniquefor using a chisel. Select a chisel that is large enough

for the job. Be sure to usc a hammer that matches thechisel; that is, the larger the chisel, the heavier thehammer. A heavy chisel will absorb the blows of alight hammer and will do virtually no cutting.

Figure 1-28-Types o f po i n t s on m e t a l - cu t t i ng ch i s e l s .

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When using a chisel for chipping, always weargoggles to protect your eyes. If others are workingclose by, see that they are protected from flying chipsby erecting a screen or shield to contain the chips.Remember that the t ime to take these precautions isbefore you start the job.

F I L E S

There are a number of different types of files incomm on u se, and each type ma y ran ge in length from3 to 18 inches.

G r a d e s

Files are graded according to the degree offineness and whether they have single- or double-cutteeth. The difference is apparent when you comparethe files in figure 1-29, view A.

Single-cut files have rows of teeth cut parallel toeach other. These teeth are set at an angle of about65 degrees with the center line. You will usesingle-cut files for sharpening tools, finish filing, anddrawfiling. They are also the best tools for smoothingthe edges of sheet metal.

Files with crisscrossed rows of teeth aredouble-cut files. The double cut forms teeth that arediamond-shaped and fast cutting. You will usedouble-cut files for quick removal of metal and for

rough work.Files are also graded according to the spacing and

size of their teeth, or their and fineness. Some ofthese grades are pictured incoarseness view B. Inaddition to the three grades shown, you may use someDEAD SMOOTH files, which have very tine teeth,and some ROUGH files, with very coarse teeth. Thefineness or coarseness of file teeth is also influencedby the length of the file. (The length of a file is thedistance from the tip to the heel, and does not includethe tang view C.) When you have a chance, compare

the actual size of the teeth of a 6-inch, single-cutsmooth file and a 12-inch, single-cut smooth file; youwill notice the 6-inch file has more teeth per inch thanthe 12-inch file.

S h a p e s

Files come inselecting a file for

different shapes. Therefore, ina job, consider the shape of the

Figure 1-29.- F i l e i n f o r m a t i on .

finished work. Some of the cross-sectional shapes areshown in figure 1-29, view D.

TRIANGULAR files are tapered on all three sides.They are used to file acute internal angles and to clearout square corners. Special triangular files are used tofile saw teeth.

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Figure 1-30. -F i l i ng ope r a t i ons .

MILL files are tapered in both width and width and thickness. HARD files, not shown, arethickness. One edge has no teeth a nd is kn own as a somewhat thicker than flat files. They taper slightlySAFE EDGE. Mill tiles are used for smoothing lathe in thickness, but their edges are parallel.work, drawfiling, and other fine, precision work. Millfiles are always single-cut. The flat or hard fibs most often used are the

double-cut for rough work and the single-cut smoothFLAT files are general-purpose files and may be file for finish work.either single- or double-cut. They are tapered in

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SQUARE files are tapered on all four sides andare used to enlarge rectangular-shaped holes and slots.ROUND files serve the same purpose for roundopenings. Small round files are often called rattailtiles.

The HALF ROUND file is a general-purpose tool.The rounded side is used for curved surfaces, and the

flat face on flat surfaces. When you file an insidecurve, use a round or half-round file whose curvemost nearly matches the curve of the work.

Kits of small files, often called swiss pattern orjewelers files, are used to fit parts of delicatemechanisms and for filing work on instruments.Handle these small files carefully because they breakeasily.

Fi l in g Op e r a t io n s

Using a file is an operation that is nearlyindispensable when working with metal. You may becrossfiling, drawfiling, using a file card, or evenpolishing metal. Lets examine these operations.

When you have finished using a file, it may benecessary to use an abrasive cloth or paper to finishthe product. Whether this is necessary depends onhow fine a finish you want on the work.

CROSSFILING. Figure 1-30, view A, shows apiece of mild steel being crossfiled. This means that

the tile is being moved across the surface of the workin approximately a crosswise direction. For bestresults, keep your feet spread apart to steady yourselfas you file with slow, full-length, steady strokes. Thefile cuts as you push it ease up on the retu rn stroke tokeep from dulling the t eeth. Keep your file clean.

View B shows the alternate positions of the filewhen an exceptionally flat surface is required. Usingeither position first, file across the entire length of thestock. Then, using the other position, file across theentire length of the stock again. Because the teeth of

the file pass over the surface of the stock from twodirections, the high spots and low spots will readily bevisible after filing in both positions. Continue filingfirst in one position or direction and then the otheruntil the surface has been filed flat. Test the flatnesswith a straightedge or with prussian blue and a surfaceplate.

D R A WFI L I N G . Drawfiling produces a finersurface finish and usually a flatter surface thancrossfiling. Small parts, as shown in view C, are bestheld in a vise. Hold the file as shown in the figure;notice that the arrow indicates that the cutting strokeis away from you wh en t he h an dle of the file is heldin the r ight hand. If the handle is held in the lefthand, the cutting stroke will be toward you. Lift the

file away from the surface of the work on the returnstroke. When drawfiling will no longer improve thesurface texture, wrap a piece of abrasive cloth aroundthe file and polish the surface as shown in figure 1-31,view A.

U S E O F F I L E C A R D . As you file, the teeth ofthe file may clog up with some of the metal filingsand scratch your work. This condition is known asPINNING. You can prevent pinning by keeping thefile teeth clean. Rubbing chalk between the teeth willhelp prevent pinning, too, but the best method is to

clean the file frequently with a FILE CARD or brush.A file card (fig. 1-32) has fine wire bristles. Brushwith a pulling motion, holding the card parallel to therows of teeth.

Always keep the file clean, whether youre filingmild steel or other metals. Use chalk liberally whenfiling nonferrous metals.

FI L I N G R O U N D - ME T AL ST O C K . Figure1-30, view D, shows that as a file is passed over thesurface of round work, its angle with the work is

changed. This r esults in a rocking motion of th e fileas it passes over the work. This rocking motionpermits al l the teeth on the t i le to make contact andcut as they pass over the works surface, thus tendingto keep the file much cleaner and thereby doing betterwork.

P O L I S H I N G A F L A T - M E T A LS U R F A C E . When polishing a flat metal surface, firstdraw t i le the su rface as shown in figure 1-30, view C.Then, when the best possible drawfiled surface hasbeen obtained, proceed with abrasive cloth, often

called emery cloth. Select a grade of cloth suited tothe drawfiling. If the drawfiling was well done, onlya tine cloth will be needed to do the polishing.

If your cloth is in a roll and if the job you arepolishing is the size that would be held in a vise, tearoff a 6- or 8-inch length of the 1- or 2-inch width. If

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Figure 1-31.- Po l i s h i ng ope r a t i ons .

you are using sheets of abrasive cloth, tear off a stripfrom the long edge of the 8- by 11-inch sheet.

Wrap the cloth around the file (fig. 1-31, view A)and hold the file as you would for drawfiling. Holdthe end of the cloth in place with your thumb. Inpolishing, apply a thin film of lubricating oil on the

Figure 1-32.-F i l e c a r d / b r us h c l eane r .

surface being polished and use a double stroke withpressure on both the forward and the backwardstrokes. Note that this is different from the drawfilingstroke in which you cut with the tile in only onedirection.

When further polishing does not appear toimprove the surface, you are ready to use the nextfiner grade of cloth. Before changing to the finergrade, however, reverse the cloth so that its back istoward the surface being polished.

Work the reversed cloth back and forth in theabrasive-laden oil as an intermediate step betweengrad es of abr asive cloth . Then, with t he solventavailable in your ship, clean the job thoroughly beforeproceeding with the next finer grade of cloth. Carefulcleaning between grades helps to ensure freedom from

scratches.

For the final polish, use a strip of crocuscloth first the face and then the back with plenty ofoil. When polishing is complete, again carefully cleanthe job with a solvent and protect it with oil or othermeans, from rusting.

In figure 1-31, A of view B shows another way topolish, in which the abrasive cloth is wrapped arounda block of wood. In B of view B, the cloth hassimply been folded to form a pad, from which a worn,

dull surface can be removed by simply tearing it offto expose a new surface.

POLISHING ROUND-METAL STOCK. Infigure 1-31, view C, a piece of round stock is beingpolished with a st rip of abr asive cloth , which isseesawed back and forth as it is guided over thesurface being polished.

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Remember that the selection of grades of abrasivecloth, the application of oil, and the cleaning betweengrades applies to polishing, regardless of how thecloth is held or used.

C a r e o f F i le s

A new file should be broken in carefully by usingit first on brass, bronze, or smooth cast iron. Just afew of the teeth will cut at first, so use a lightpressure to prevent tooth breakage. Do not break ina new file by using it first on a narrow surface.

Protect the file teeth by hanging your files in arack when they are not in use or by placing them indrawers with wooden partitions. Your files should notbe allowed to rust keep them away from water andmoisture. Avoid getting the files oily. Oil causes afile to slide across the work and prevents fast, cleancutting. Files that you keep in your toolbox should be

wrapped in paper or cloth to protect their teeth andprevent damage to other tools.

Never use a file for prying or pounding. The tangis soft and bends easily. The body is hard a ndextremely brittle. Even a slight bend or a fall to thedeck may cause a file to snap in two. Do not strikea file against the bench or vise to clean it use a filecard.

S a f e t y

Never use a file unless it is equipped with atight-fitting handle. If you use a file with out t hehan dle and it bumps something or jams to a su ddenstop, the tang may be driven into your hand. To puta handle on a file tang, drill a hole in the handle,slightly smaller than the tang. Insert the tang end, andthen tap the end of the ha ndle to scat i t firm ly. Makesure you get the handle on straight .

TWIST DR ILLS

Making a hole in a piece of metal is generally a

simple operation, but in most cases an important,precise job. A large number of different tools andmachines have been designed so that holes may bemade speedily, economically, and accurately in allkinds of material.

To be able t o use t hese tools efficient ly, it isimportant that you become acquainted with them. Themost common tool for making holes in metal is the

twist drill. It consists of a cylindrical piece of steelwith spiral grooves. One end of the cylinder ispointed, while the other end is shaped so that i t maybe attached to a drilling machine. The grooves,usually called FLUTES, may be cut into the steelcylinder, or the flutes may be formed by twisting aflat piece of steel into a cylindrical shape.

The principal parts of a twist drill are the body,the shank, and the point (fig. 1-33). The dead centerof a drill is the sharp edge at the extreme tip end ofthe drill. It is formed by the intersection of thecone-shaped surfaces of the point and should alwaysbe the exact center of the axis of the drill. The pointof the drill should not be confused with the deadcenter. The point is the entire cone-shaped surface atthe end of the drill.

Figure 1-33.-Tw i s t d r i l l nom enc l a t u r e .

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The lip or cutting edge of a drill is that part of thepoint that actual ly cuts away the metal when dri l l inga hole. It is ordinarily as sharp as the edge of a knife.There is a cutting edge for each flute of the drill .

The shan k is the pa rt of the dr i ll that fi ts into thesocket, spindle, or chuck of the drill press. Severaltypes exist (fig. 1-34).

The maintenance of twist drills and more abouthow to use them on specific jobs are discussed later.

P U N C H E S

A hand punch is a tool that is held in the handand struck on one end with a hammer. There aremany kinds of punches designed to do a variety of

jobs. Figure 1-35 shows several types of punches.Most punches are made of tool steel. The part held inthe h an d is usua lly octagonal in sha pe, or it m ay be

knurled. This prevents the tool from slipping aroundin the hand. The other end is shaped to do aparticular job.

When you use a punch, there are two things toremember:

1. When you hit the punch, you do not want itto slip sideways over your work.

2. You do not want the hammer to slip off thepunch and strike your fingers. You can eliminate both

of these troubles by holding the punch at right anglesto the work and striking the punch squarely with yourhammer.

Figure 1-34.-R e p r e s e n t a t i v e s h a n k s .

Fi gur e 1 - 35 .- P u n c h e s .

The center punch, as the name implies, is used formarking the center of a hole to be drilled. If you tryto drill a hole without first punching the center, thedrill will wander or walk away from the desiredcenter.

Another use of th e center pun ch is to ma kecorresponding marks on two pieces of an assembly topermit reassembling in the original positions. Beforetaking a mechanism apart , make a pair of centerpunchmarks in one or more places to help in

reassembly. To do this, select places, staggered asshown in figure 1-36, where matching pieces are joined. First, clean the places selected. Then, scribea line across the joint, a nd center punch t he line onboth sides of the joint, with single and double marks

Figure 1-36.-P u n c h m a r k i n g m a t i n g p a r t s .

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as shown to eliminate possible errors. In reassembly,refer first to the sets of punchmarks to determine theapproximate position of the parts. Then line up thescribed lines to determine the exact position.

To make the intersection of two layout lines, bringthe point of the prick punch to the exact point ofintersection and tap the punch lightly with a hammer.If inspection shows that the exact intersection and the

punchmark do not coincide, as in view A offigure1-37, slant the punch as shown in view B and strikeagain with the hammer, thus enlarging the punchmarkand centering it exactly. When the intersection hasbeen correctly punched, finish off with a light blow onthe punch held in an upright position. View C showsthe corrected punchmark.

D RIF T punches, som et im es ca l led startingpunches, have a long taper from the tip to the body.They are made that way to withstand the shock ofheavy blows. They may be used for knocking out

rivets after the heads have been chiseled off or forfreeing pins that are frozen in their holes.

After a pin has been loosened or partially drivenout, the drift punch may be too large to finish the job.The follow-up tool to use is the PIN PUNCH. It isdesigned to follow through the hole without jamming.Always use the largest drift or pin punch that will titthe hole. These punches usually come in sets of threeto five assorted sizes. Both of these punches willhave flat ends, never edged or rounded.

Figure 1-37.-Ma r k in g th e in t e r s e c t io n o f l i n e s w i th a p r i c k

To remove a bolt or pin that is extremely tight,star t with a drif t punch that has an end diameter thatis slightly smaller than the diameter of the object youare removing. As soon as the bolt or pin loosens,finish driving it out with a pin punch. Never use apin punch for starting a pin, because it has a slimshan k and a ha rd blow may cause it to bend or break.

For assembling units of a machine, an

ALIGNMENT (aligning) punch is inva luable. It isusually about 1-foot long and has a long gradual taper.Its purpose is to line up holes in mating parts.

Hollow metal-cutting punches are made fromhardened tool steel. They are made in various sizesand are used to cut holes in light gauge sheet metal.

Other punches have been designed for specialuses. One of these is the soft-faced drift. It is madeof brass or fiber and is used for such jobs as removingshafts, bearings, and wrist pins from engines. It is

generally heavy enough to resist damage to itself, butsoft enough not to injure the finished surface on thepart that is being driven.

You may have to make gaskets of rubber, cork,leather, or composition materials. For cutting holes ingasket materials , a hol low shank GASKET PUNCHmay be used (fig. 1-35). Gasket punches come in setsof various sizes to a ccomm odate sta nda rd bolts an dstuds. The cutting end is tapered to a sharp edge toproduce a clean uniform hole. To use the gasketpunch, place the gasket material to be cut on a piece

of har d wood or lead so th at th e cutting edge of thepunch will not be damaged. Then strike the punchwith a hammer, driving i t through the gasket whereholes are required.

TAP S AND DIES

Taps and dies are used to cut threads in metal,plast ics, or har d ru bber. The ta ps ar e used for cut t inginternal threads, and the dies are used to cut externalthreads. There are many different types of taps.However, the most common are the taper, plug,

bottoming, and pipe taps (fig. 1-38).

The taper (starting) hand tap has a chamfer lengthof 8 to 10 threads. These taps are used when start inga tapping operat ion and when tapping through holes.

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p u n c h .


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Fi gu r e 1 -38 .-T y p e s o f c o m m o n t a p s .

Plug hand taps have a chamfer length of 3 to 5threads and are designed for use after the taper tap.

Bottoming hand taps are used for threading thebottom of a blind hole. They have a very shortchamfer length of only 1 to 1 1/2 threads for thispurpose. This tap is always used after the plug taphas been used. Both the taper and plug taps shouldprecede the use of the bottoming hand tap.

Pipe taps are used for pipe fittings and otherplaces where extremely tight fits are necessary. Thetap diameter, from end to end of the threaded portion,increases at the rate of 3/4 inch per foot. All thethreads on this tap do the cut t ing, as compar ed to thestraight taps, where only the nonchamfered portiondoes the cutting.

Dies are made in several different shapes and areof the solid or adjustable type. The square pipe die(fig. 1-39) wil l cut American Standard Pipe thread

Fi gu r e 1 -39 .-Type s o f s o l i d d i e s .

only. It comes in a variety of sizes for cutting threadson pipe with diameters of 1/8 inch to 2 inches.

A rethreading die (fig. 1-39) is used principallyfor dressing over bruised or rusty threads on screws orbolts. It is available in a variety of sizes forrethreading American Standard Coarse and Finethreads. These dies are usu al ly hexagon in shape a ndcan be turned with a socket, box, open-end, or anywrench that will fit . Rethreading dies are available insets of 6, 10, 14, and 28 assorted sizes in a case.

Round split adjusta ble dies (fig. 1-40) are calledBurton dies and can be used in either hand diestocksor machine holders. The adjustment in the screwadjusting type is made by a fine-pitch screw, whichforces the sides of the die apart or allows them tospring together. The adjustment in the open adjustingtype is made by means of three screws in the holder,one for expanding and two for compressing the dies.

Two piece collet dies (fig. 1-40) are used with a

collet cap (fig. 1-41) and collet guide. The die halvesare placed in the cap slot and are held in place by theguide, which screws into the underside of the cap.The die is adjusted by setscrews at both en ds of theinterval slot. This type of adjustable die is issued invarious sizes to cover the cutting ranges of AmericanStandard Coarse and Fine and special-form threads.Diestocks to hold the dies come in three differentsizes.

Two-piece rectangular pipe dies (fig. 1-40) a reavailable to cut American Standard Pipe threads.

They ar e held in ordinar y or ra tchet-type diestocks(fig. 1-42).

Threading sets are available in many differentcombinations of taps and dies, together with diestocks,tap wrenches, guides, and necessary screwdrivers and

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Never attempt to sharpen taps or dies. Sharpeningwrenches to loosen and tighten adjusting screws and of taps and dies involves several highly precise cuttingbolts. Figure 1-43 illustrates typical threading sets for processes which involve the thread characteristics andpipe, bolt s, and screws. cham fer . These sha rpen ing procedur es m ust be done

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Figure 1 -41 .-D i e s t o c k s , d i e c o l l e t , a n d t a p w r e n c h e s .

F igure 1 -40 .-T y p e s o f a d j u s t a b l e d i e s .


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Figure 1-42.-Ad ju s t a b le d i e g u id e a n d r a t c h e t d i e s to c k s .

by experienced personnel to maintain the accuracy andthe cutting effectiveness of taps and dies.

Keep taps and dies clean and well oiled when not

in use. Store them so that they do not contact each

other or other tools. For long periods of storage, coattaps and dies with a rust-preventive compound, placein individual or standard threading set boxes, and storein a dry place.

SCRE W AND TAP EXTRACTORS

Screw extractors are used to remove brokenscrews without damaging the surrounding material or

Figure 1-44. -S c r e w a n d t a p e x t r a c t o r .

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Fi gu r e 1 -43 .-T a p a n d d i e t h r e a d s e t s .


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the threaded hole. Tap extractors are used to removebroken taps (fig. 1-44, view A).

Screw extractors (view B) are straight, withspiraling flutes at one end. These extractors areavailable in sizes to remove broken screws having1/4- to 1/2-inch outside d iamet ers (ODs). Spiraltapered extractors are sized to remove screws andbolts from 3/16 inch to 2 1/8 inches OD.

Most sets of extractors include twist drills and adrill guide. Tap extractors are similar to the screwextractors and are sized to remove taps ranging from3/16 inch to 2 1/8 inches OD.

To remove a broken screw or tap with a spiralextractor, first drill a hole of proper size in the screwor tap. The size hole required for each screwextractor is stamped on it. The extractor is theninserted in the hole, and turned counterclockwise toremove the defective component.

PIPE AND TUBING CUTTERS ANDFL A R IN G T O O L S

Pipe cutters (fig. 1-45) are used to cut pipe madeof steel, brass, copper, wrought iron, or lead. Tubecutters (fig. 1-45) are used to cut tubing made of iron,steel, brass, copper, or aluminum. The essentialdifference between pipe and tubing is that tubing has

considerably thinner walls. Flaring tools (fig. 1-46)are used to make flares in the ends of tubing.

Two sizes of hand pipe cutters are generally usedin the Navy. The No. 1 pipe cutter has a cuttingcapacity of 1/8 inch to 2 inches, and the No. 2 pipecutter has a cutting capacity of 2 to 4 inches. Thepipe cutter (fig. 1-45) has a special alloy-steel cuttingwheel and two pressure rollers, which are adjusted and

tightened by turning the handle.

Most TUBE CUTTERS closely resemble pipecutters, except that they are of lighter construction. Ahand screw feed tubing cutter of l/8-inch to 1l/4-inch capacity (fig. 1-45) has two rollers withcutouts located off center so that cracked flares maybe held in them and cut off without waste of tubing.It also has a retractable cutter blade, which is adjustedby turning a knob. The other tube cutter shown isdesigned to cut tubing up to and including 1 inch OD.Rotation of the triangular portion of the tube cutterwithin the t ubing wil l el iminat e any bur rs.

FLARING TOOLS (fig. 1-46) are used to flaresoft copper, brass, or aluminum. The single flaring

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Figure 1 -45 .-P i p e a n d t u b i n g cu t t e r s .


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tool consists of a split die block, which has holes for3/16-, 1/4-, 5/16-, 3/8-, 7/16-, and 1/2-inch OD tubing;a clamp to lock the tube in the die block; and a yoke,which s lips over t he die block a nd ha s a compressorscrew and a cone that forms a 45-degree flare or abell shape on the end of the tube. The screw has aT-ha ndle. A double flarin g tool ha s t he a dditiona lfeature of adapters, which turn in the edge of the tubebefore a regular 45-degree double flare is made. Itcons ist s of a die block with holes for 3/16-, 1/4-,

5/16-, 3/8-, and 1/2-inch tubing; a yoke with a screwand a flaring cone; plus five adapters for different sizetubing, all carried in a metal case.

SCREWDRIVERS

A screwdriver is one of the most basic ofhandtools. It is also the most frequently abused of allhand tools. It is designed for one function only todrive and to remove screws.not be used as a pr y bar , apunch.

STANDARD

There are three main

A screwdriver shouldscraper, a chisel, or a

par ts to a s tandardscrewdriver. The portion you grip is called thehandle, the steel portion extending from the handle isthe shank, and the end that fits into the screw is calledthe blade (fig. 1-47).

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Figure 1-46.-Flar ing too ls .

Figure 1-47.-Ty p es o f sc r ewd r iv e r s .


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The steel shank is designed to withstandconsiderable twisting force in proportion to its size,and the tip of the blade is hardened to keep it fromwearing.

Standard screwdrivers are classified by size,according to the combined length of the shank andblade. The most common sizes range in length from2 1/2 to 12 inches. There are many screwdriverssmaller and some larger for special purposes. Thediameter of the sha nk, and t he width and t hickness ofthe blade are generally proportionate to the length, butagain there are special screwdrivers with long thinshan ks, short t hick sha nks, and extra wide or extranarrow blades.

When using a screwdriver, you should select theproper size so th at th e blade fits t he screw slotproperly. This prevents burring the slot and reducesthe force required to hold the driver in the slot. Keep

the shank perpendicular to the screw head (fig. 1-48).

R E C E S S E D

Recessed screws are now available in variousshapes. They have a cavity formed in the head andrequire a specially shaped screwdriver. The clutch tip(fig. 1-47) is one shape, but the more common includethe Phillips, Reed and Prince, and newer Torq-Settypes (fig. 1-49). The most common type of screwfound is the Phillips head. This requires aPhillips-type screwdriver (fig. 1-47).

Ph i l l i p s Sc r ewd r iv e r

The head of a Phillips-type screw has a four-wayslot into which the screwdriver tits. This prevents thescrewdriver from slipping. Three standard-sizedPhillips screwdrivers handle a wide range of screwsizes. Their ability to hold helps to prevent damagingthe slots or the work surrounding the screw. It is apoor practice to try to use a standard screwdriver on

Figure 1-48. -Pos i t i on i ng s c r ew dr i ve r s .

Figure 1-49.-C om par i s on o f Ph i l l i p s , R eed and P r i nce , andT o r q S e t s c r e w h e a d s .

a Phillips screw, because both the tool and screw slotwill be damaged.

R e e d a n d P r i n c e S c r e w d r i v e r

Reed and Prince screwdrivers are notinterchangeable with Phillips screwdrivers. Therefore,always use a Reed and Prince screwdriver with Reed

and Prince screws, and a Phillips screwdriver withPhillips screws, or a ruined tool or ruined screwheadwill result.

To distinguish between these similar screwdrivers,refer to figure 1-50.

The Phillips screwdriver has about 30-degreeflukes and a blunt end, while the Reed and Prince has45-degree flukes and a sharper, pointed end. ThePhillips screw has beveled walls between the slots; theReed and Prince, straight, pointed walls. In addition,

the Phillips screw slot is not as deep as the Reed andPrince slot.

Figure 1-50.-Ma t ch i ng c r os s - s l o t s c r ew s and s c r ew dr i ve r s .

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Additional ways to identify the right screwdriverare as follows:

1. If the screwdriver tends to stand up un assistedwhen the point is put in the head of a vertical screw,it is probably the proper one.

2. The out line of the end of a Reed a nd P rincescrewdriver is approximately a right angle, as seen infigure 1-50.

3. In general, Reed and Prince screws are usedfor airframe structural applications, while Phillipsscrews are found most often in component assemblies.

T o r q - S e t S c r e w s

Torq-Set machine screws (offset cross-slot drive)have recently begun to appear in new equipment. Themain advantage of the newer type is that more torquecan be applied to its head while tightening orloosening than to any other screw of comparable sizeand material without damaging the head of the screw.

Torq-Set machine screws are similar in appearanceto the more familiar Phillips machine screws.

Since a Phillips driver could easily damage aTorq-Set screwhead, making it difficult if notimpossible to remove the screw even if the proper toolis later used, maintenance personnel should be alert tothe differences (fig. 1-49) and make sure the proper

tool is used.OFFSET SCREWDRIVERS

An offset screwdriver (fig. 1-47) may be usedwhere there is not sufficient vertical space for astandard or recessed screwdriver. Offset screwdriversare constructed with one blade forged in line andanother blade forged at r ight an gles to the sha nkhandle. Both blades are bent 90 degrees to the shankhandle. By alternating ends, most screws can beseated or loosened even when the swinging space is

very restricted. Offset screwdrivers are made for bothstandard and recessed-head screws.

R A T C H E T SC R E W D R IVE R

For fast, easy work, the ratchet screwdriver (fig.1-47), is extremely convenient, as it can be usedone-handed and does not require the bit to be liftedout of the slot after each turn. It may be fitted with

either a standard-type bit or a special bit for recessedheads. The ratchet screwdriver is most commonlyused by the woodworker for driving screws in softwood.

S A F E T Y

Screwdrivers, like an y oth er h an d t ool, aredangerous when not used properly. Therefore, thefollowing safety precautions should always befollowed:

Never use a screwdriver to check an electricalcircuit.

Never try to tur n a screwdriver with a pair ofpliers.

Do not hold work in your hand while using ascrewdriver if the point slips, it can cause a bad cut.Hold the work in a vise, with a clamp, or on a solidsurface. If that is impossible, you will always be safeif you follow this rule: NEVER GET ANY PART OFYOUR BODY IN FRONT OF THE SCREWDRIVERBLADE TIP. That is a good safety rule for any sharpor pointed tool.

P L I E R S

Pliers are made in many styles and sizes and areused to perform many different operations. Pliers areused for cutting purposes, as well as holding andgripping small articles in situations where it may beinconvenient or impossible to use hands. Figure 1-51shows several different kinds.

The combination pliers are handy for holding orbending flat or round stock. The long-nosed pliers areless rugged, and break easily if you use them onheavy jobs. Long-nosed pliers, commonly calledneedle-nose pliers, are especially useful for holdingsmall objects in tight places and for making delicateadjustments. The round-nosed kind are handy whenyou n eed to crimp sheet m etal or form a loop in a

wire. The diagonal cutting pliers, commonly called"diagona ls" or dikes, ar e designed for cutting wireand cotter pins close to a flat surface and areespecially useful in the electronic and electrical fields.The duckbill pliers are used extensively in aviationa reas .

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Here are two important rules for using pliers:

1. Do not make pliers work beyond theircapacity. The long-nosed kind is especially delicate.It is easy to spring or break them, or nick their edges.

After that, they are practically useless.2. Do not use pliers to turn nuts. In just a few

seconds, a pair of pliers can damage a nut. Pliersmust not be substi tuted for wrenches.

S L I P -J O I N T P L I E R S

Slip-joint pliers (fig. 1-52) are pliers with straight,serrated (grooved) jaws, and pivot where the jaws arefastened together to move to either of two positions tograsp small- or large-sized objects better.

Slip-joint combination pliers are pliers similar toth e slip-joint pliers just described but with t headditional feature of a side cutter at the junction of the

jaws. This cutter consists of a pair of square-cutnotches, one on each jaw, which act like a pair ofshears when an object is placed between them and the

jaws closed.

F i g u re 1 -5 1 .-P l i e r s .

WRENCH PLIERS

Wrench pliers (visegrips) (fig. 1-53), can be usedfor holding objects regardless of their shape. A screwadjustment in one of the handles makes them suitable

for several different sizes. The jaws of wrench pliersmay have standard serrat ions such as the pliers justdescribed, or they may have a clamp-type jaw. Theclamp-type jaws are generally wide and smooth andare used primarily when working with sheet metal .

Wrench pliers have an advantage over other typesof pliers in that you can clamp them on an object andthey will stay. This will leave your hands free forother work.

A craftsman uses this tool a number of ways. It

may be used as a clamp, speed wrench, portable vise,and for many other uses where a locking, plier-typejaw ma y be used. These pliers can be adjusted tovarious jaw openings by turning the knurled, adjustingscrew at the end of the handle (fig. 1-53). Wrenchpliers can be clamped a nd locked in position bypulling the lever toward the handle.

CAUTION

Wrench pliers should be used with care,since the teeth in the jaws tend to damage the

object on which they are clamped. Theyshould not be used on nuts, bolts, tubefittings, or other objects that must be reused.

Figure 1 -52 .-S l i p - j o i n t p l i e r s .

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Figure 1 -53 .-W r e n c h p l i e r s .

same as t he pliers just described, but the jaw openingadjustment is effected differently. Groove-joint pliershave grooves on one jaw and lands on the other. Theadjustment is effected by changing the position of thegrooves and lands. The groove-joint pliers are lesslikely to slip from th e adjustm ent setting whengripping an object. The groove-joint pliers will onlybe used where it is impossible to use a more adaptedwrench or holding device. Many nuts and bolts andsurrounding parts have been damaged by improper useof groove-joint pliers.

WATER-PUMP PLIERSDIAGONAL PLIERS

Water-pump pliers were originally designed fortightening or removing water-pump packing nuts.They were excellent for this job because they have a

jaw adjustable to seven different positions.Water-pump pliers (fig

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Aviation Boatswain’s Mate E 3 & 2