03.Tools,Shop Equipment and Measuring

7/30/2019 03.Tools,Shop Equipment and Measuring

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2008 Pearson Education, Inc.Pearson Prentice Hall - Upper Saddle River, NJ 07458

Automotive Technology: Principles, Diagnosis, and Service, 3rd EditionBy J ames D. Halderman


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Explain the terms used to identify bolts andother threaded fasteners. Explain the strength ratings of threaded

fasteners.

Describe the proper use of nonthreaded

fasteners. Discuss how snap rings are used.

After studying Chapter 8, the reader shouldbe able to:

OBJECTIVES:


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bolts cap screws capil lary action Christmas treeclips cotter pins crest

die grade Helical insert Helicoil jam nut

metric bolts pal nut penetrating oil pitch pop rivet

prevailing torque nuts

self-tapping screw snap ring stud tap tensile

strength threaded insert

UNC (unified national coarse) UNF (unified national

fine) washers

KEY TERMS:


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THREADED FASTENERS

Most of the threaded fasteners used on vehicles are cap screws.They are calledcap screws when they are threaded into a casting.

Automotive techs usually refer to these as bolts regardless of howthey are used. In this chapter, they are called bolts.

Sometimes, studs are used for threaded fasteners. A stud is a

short rod with threads on both ends. Often, a stud will have

coarse threads on the end screwed into the casting, and fine

threads on the other. A nut is used to hold the parts together.

The fastener threads mustmatch the threads in the casting or nut.

Continued


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Figure 81 The dimensions of a typical bolt showing where sizes are measured.

Threads may be measured in

fractions of an inch (fractional)

or in metric units.

The size is measured across

the outside of the threads, or

the crest of the thread.

Continued


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Figure 82 Thread pitch gauge used to measure the pitch of the thread. This bolt has

13 threads to the inch.

Threads are either coarse or fine. Coarse threads are calledUnified

National Coarse (UNC) and fine threads calledUnified NationalFine (UNF). Standard combinations of sizes and number of threads

per inch (calledpitch) are used. Pitch can be measured with a

thread pitch gauge, as shown here.

Continued


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Figure 83 Bolts and screws have many different heads which determine what tool must be

used.

Bolts are identified by

diameter and length asmeasured from below

the head, not by the

size of the head or

the wrench used.

Bolts and screws have

many different-shapedheads, as shown here.

Continued


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Fractional thread sizes are specified by the diameter in fractions

of an inch and number of threads per inch.

Typical UNC thread sizes would be 5/16-18 and 1/2-13.

Similar UNF thread sizes would be 5/16-24 and 1/2-20.

Figure 84

The American National System

is one method of sizing fasteners.

See the complete ANS thread chart on Page 52 of your textbook.


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Metric Bolts

The size of a metric bolt is specified by the letterMfollowed bydiameter in millimeters across the outside (crest) of the threads.

Typical metric sizes would be M8 and M12. Fine metric threadsare specified by the thread diameter followed byXand the

distance between the threads measured in millimeters (M8 1.5).

See the complete metric

thread chart on Page 53

of your textbook.

Figure 85 The metric system specifies

fasteners by diameter, length, and pitch.


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GRADES OF BOLTS

Bolts are made from different types of steel. Some are stronger thanothers. The strength or classification of a bolt is called the grade.

Bolt heads are marked to indicate grade strength.

Graded bolts are common in the suspension, but can be used almost

anywhere in the vehicle.

Actual grade is two more than the number of lines on the bolt head.

Metric bolts have a decimal number to indicate the grade. More

lines or a higher grade number indicate a stronger bolt. In some

cases, nuts and machine screws have similar grade markings.

Continued


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SAE BOLT GRADES

See the complete SAE

Bolt Grade chart on

Page 53 of your textbook.


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Higher grade bolts usually have threads that are rolled rather than

cut, which also makes them stronger.

CAUTION: Never use hardware store (nongraded) bolts, studs, or nutson any vehicle steering, suspension, or brake component. Always use the

exact size and grade of hardware that is specified and used by the vehicle

manufacturer.

CAUTION: Never use hardware store (nongraded) bolts, studs, or nutson any vehicle steering, suspension, or brake component. Always use the

exact size and grade of hardware that is specified and used by the vehicle

manufacturer.

Figure 86 Stronger

threads are created by

cold-rolling a heat-treated bolt blank

instead of cutting the

threads using a die.


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TENSILE STRENGTH

Graded fasteners have higher tensile strength than nongradedfasteners. Tensile strength is maximum stress under tension

(lengthwise force) without failure of the fastener.

Tensile strength is specified in pounds per square inch (psi).

The strength and type of steel used in a bolt is indicated by a

raised mark on the head of the bolt, and depends on the standard

to which the bolt was manufactured.

Most bolts used in machinery are made to SAE Standard J429.

See the SAE Bolt Tensile Strength chart.

Continued


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SAE BOLT TENSILE STRENGTH

See the complete SAE Bolt

Tensile Strength chart on

Page 53 of your textbook.


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Metric bolt tensile strength property class is shown on the head of

the bolt as a number, such as 4.6, 8.8, 9.8, and 10.9; the higher the

number, the stronger the bolt.

Figure 87 Metric bolt (cap screw) grade markings and approximate tensile strength.


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A common mistake made by persons new to the automotive field is tothink that the size of a bolt or nut is the size of the head. The size of thebolt or nut (outside diameter of the threads) is usually smaller than the sizeof the wrench or socket that fits the head of the bolt or nut. Examples are

given in the following tables:

A common mistake made by persons new to the automotive field is tothink that the size of a bolt or nut is the size of the head. The size of thebolt or nut (outside diameter of the threads) is usually smaller than the sizeof the wrench or socket that fits the head of the bolt or nut. Examples are

given in the following tables:

A 1/2-Inch Wrench Does Not Fit a 1/2-Inch Bolt

* European (Systme International dUnits-SI) metric.

HINT: An open-end wrench can be used to gauge bolt sizes. A 3/8-in.

wrench will fit the threads of a 3/8-in. bolt.

Wrench Size Thread Size

7 /16 in. 1 /4 in.

1 /2 in. 5 /16 in.9 /16 in. 3 /8 in.

5 /8 in. 7 /16 in.

3 /4 in. 1 /2 in.

Wrench Size Thread Size

10 mm 6 mm

12 or 13 mm* 8 mm14 or 17 mm* 10 mm


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NUTS

Most nuts used on cap screws have the same hex size as the capscrew head. Inexpensive nuts may use a hex size larger than the

cap screw head.

Metric nuts are often marked with dimples to show their strength.

More dimples indicate stronger nuts.

Nuts can be kept from loosening with a nylon washer or a nylon

patch or strip on the threads.

Continued


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NOTE: Most of these locking nuts are grouped together and are

commonly referred to as prevailing torque nuts. This means the nut

will hold its tightness or torque and not loosen with movement or

vibration. Most prevailing torque nuts should be replaced whenever

removed to ensure that the nut will not loosen during service. Always

follow the manufacturers recommendations. Anaerobic sealers, such asLoctite , are used on the threads where the nut or cap screw must be both

locked and sealed.

Continued


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Figure 88 Types of lock nuts. On the left, a nylon ring; in the center, a distorted shape;

and on the right, a castle for use with a cotter key.

Some nuts and cap screws use interference fit threads to preventaccidental loosening. The shape is distorted or a section of the

threads is deformed.


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TAPS AND DIES

Taps and dies are used to cut threads.

Taps cut threads in holes drilled to an exact size.

A die cuts threads on round rod or studs.

Tapered tap. The most commonly used tap, designed to cut

threads by gradually enlarging the threaded hole.Bottoming tap. A flat bottom to allow it to cut threads to the

bottom of a drilled hole.

Taps There are two commonly used types of taps:

Continued


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Figure 89 A typical bottoming tap used to create threads in holes that are not open, but

stop in a casting, such as an engine block.

Continued


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Figure 810 Many taps, especially larger ones, have the tap dril l size printed on the top.

All taps must be used in the

proper size hole called atap drill size.

This information is oftenin a chart that is included

with a tap and die tool set

or stamped on the tap itselfas shown here.

Continued


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Figure 811 A die is used to cut threads on a metal rod.

Dies A die is a hardened steelround cutter with teeth on the

inside of the center hole.

A die is rotated using a die

handler over a rod to create

threads.

Continued


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Figure 812a & b A T- handle (a) is used to hold and rotate small taps. A tap wrench (b) is used

to hold and drive larger taps.

A small tap can be held usinga T-handle. For larger taps a

tap handle is needed to apply

needed force to cut threads.

(a)

(b)

Continued


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Figure 813 A die handle used to rotate a die while cutting threads on a metal rod.

Continued


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Tap Usage Be sure that the hole is the correct size for the tap.

Insert tap straight into the hole. Lubricate using tapping lubricant.

Rotate the tap about one full turn clock wise, then reverse

direction one-half turn to break the chip which is created.

Repeat until the hole is completely threaded.

Die Usage A die should be used on the specified diameter rod forthe size of the thread. Install the die securely into the die handle.

Lubricate the die and rod and place the die onto the end of the rod

to be threaded. Rotate handle one full turn clockwise, then reverse

direction and about a half turn counterclockwise to break the chip.

Repeat until threaded portion is completed.


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THREAD PITCH GAUGE

A thread pitch gauge is a hand tool that has the outline of variousthread sizes machined on stamped blades. To determine the thread

pitch size of a fastener, the technician matches the thread of the

thread pitch gauge to the threads of the fastener.

Figure 814 A typical thread pitch gauge.


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A tap is a cutting tool, designed to cut new threads. A thread chaser hasmore rounded threads, designed to clean dirty threads without removingmetal. When cleaning threads, it is best to use a thread chaser rather than

a tap to prevent removing metal, which would affect the fit of the bolt.

A tap is a cutting tool, designed to cut new threads. A thread chaser hasmore rounded threads, designed to clean dirty threads without removingmetal. When cleaning threads, it is best to use a thread chaser rather than

a tap to prevent removing metal, which would affect the fit of the bolt.

What is the difference between a tap and a thread chaser?

Figure 815 A thread chaser is shown at

the top compared to a tap on the bottom.

A thread chaser is used to clean threads

without removing metal.


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Sheet metal screws are

fully threaded screws

with a point for use in

sheet metal.

Also calledself-tapping

screws, they are used inmany places on vehicles,

including fenders, trim,

and door panels.

SHEET METAL SCREWS

Figure 816 Sheet metal screws

come with many head types.

Continued


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Sheet metal screws are used in unthreaded holes and the sharp

threads cut threads as they are installed, for a quick and easy

installation.

The sheet metal screw can easily strip out the threads when used

on the same part over and over, so care is needed.

When reinstalling, first turn the screw lightly backwards until the

thread drops into the existing thread in the screw hole. Turn the

screw in; if it threads in easily, continue to tighten.

If the screw turns hard, stop and turn backwards about a half turn

to locate the existing thread and try again. This technique can helpprevent stripped holes in sheet metal and plastic parts.

Continued


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Sheet metal screws are sized according to their major thread

diameter.


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WASHERS

Washers are often used undercap screw heads and under

nuts.

Plain flat washers are used

to provide an even clamping

load around the fastener.

Lock washers are added to

prevent accidental loosening.

In some accessories, washers

are locked onto the nut to

provide easy assembly.

Figure 817 Various types of nuts (top) and

washers (bottom) serve different purposes

and all are used to secure bolts or cap screws.


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SNAP RINGS AND CLIPS

Snap Rings Constructed of spring steel and used to attach partswithout using a threaded fastener. There are different types of snap

rings. Most require special snap ring pliers to release or install.

Door Panel Clips Interior door panels and other trim pieces are

usually held in place with plastic clips, often calledChristmas tree

clips due to the tapered and fluted shape. A special tool is often

used to remove door panels.

CAUTION: Use extreme care when removing panels that use plasticor nylon clips. It is very easy to damage the door panel or clip during

removal.

CAUTION: Use extreme care when removing panels that use plasticor nylon clips. It is very easy to damage the door panel or clip duringremoval.

Continued


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Figure 818 Some different types of snap rings. An internal snap ring fits inside of a

housing or bore, into a groove. An external snap ring f its into a groove on the outside of a

shaft or axle. An E-Clip fits into a groove in the outside of a shaft. A C-Clip shown is used to

retain a window regulator handle on its shaft.

Expanding (internal)

Contracting (external)

E-clip

C-clip

Holeless snap rings in

expanding and contracting

styles

Types of snap rings include:

Continued


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Figure 820 Plastic or metal trim tools

are available to help the technician remove

interior door panels and other trim without

causing harm.

Figure 819 A typical door panel retaining clip.


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Pins Cotter pins, also called a cotter key, keep linkage or a

threaded nut in place or retained. Cotteris an Old English verb

meaning to close or fasten.

Other types of pins include clevis pins, roll pins, and hair pins.They are used on shafts, shift and cable linkages.

The clevis pin is held in place with a cotter pin. Taper and roll pins

are driven in, held by friction. Hair pins snap into a shaft groove.

Figure 821

Pins come in

various types.


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Rivets Used to retain components, such as window mechanisms,

not requiring routine removal and/or do not have access to the

back side for a nut.

A drill is usually used to remove a rivet. A rivet gun is needed to

properly install a rivet. Some rivets are plastic and are used tohold some body trim pieces.

The most common type of rivet is called a pop rivet. As the rivet

tool applies force to the shaft of the rivet, it causes the rivet to

expand and tighten the two pieces together.

When the shaft of the rivet, which looks like a nail, is pulled tomaximum, it breaks, causing a pop sound.

Continued


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Both types of blind rivets require the use of a rivet gun to install.

The straight rivet is placed through the workpieces and peenedover with a ball-peen hammer or an air-operated tool. The plastic

rivet is used with a rivet gun to install some body trim parts.

Figure 822 Various

types of rivets.


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Figure 823 All of the nuts shown are used by themselves except for the pal nut, which is

used to lock another nut to a threaded fastener so they will not be loosened by vibration.

Locking Nuts Jam nuts

screw on top of a regular nut

and jam against the regular

nut to prevent loosening.

A jam nut is so called

because of its intended use,rather than a special design.

Also calledpal nuts, somejam nuts are thinner than a

standard nut.

Continued


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There are also various self-locking nuts. Some have threads bent

inward to grip the threads of the bolt. Some are oval-shaped at one

end to fit tightly on a bolt.

Fiber lock nuts have a fiber, plastic or nylon insert near the top of

the nut or inside it. When the bolt turns through, it cuts threads inthe fiber or plastic, putting drag on the threads to prevents

loosening.

Flat washers are placed underneath a nut to spread the load over

a wide area and prevent gouging of the material. However, flat

washers do not prevent a nut from loosening.

Continued


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Figure 824 A castellated nut is locked in place

with a cotter pin.

One of the oldest types ofretaining nuts is the castle

nut, which looks like a

small castle, with slotsfor a cotter pin.

A castellated nut is used

on a bolt that has a hole

for the cotter pin.

Continued


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Lock washers are designed to prevent a nut from loosening.

Spring-type lock washers resemble a loop out of a coil spring.As the nut or bolt is tightened, the washer is compressed. The

tension holds the fastener against the threads to prevent loosening.

Lock washers should not be used on soft metal, like aluminum, as

the sharp ends would gouge badly if removed and replaced often.

Another type is the star washer. The teeth on a star washer can be

external or internal, and bite into metal because they are twisted to

expose their edges.

Star washers are used often on sheet metal or body parts. The

waves in this washer make it look like a distorted flat washer.

Continued


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HOW TO AVOID BROKEN FASTENERS

Try not to break, strip, or round off fasteners. There are severalprecautionary steps to minimize the number of fasteners you

damage.

Never force fasteners loose. If a bolt or nut will not come loose

with normal force, try tightening slightly and then backing out.

Turning the fastener the other way sometimes will break corrosion

loose. Another method is to rest a punch on the head of a bolt and

strike a sharp blow with a hammer.

Continued


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Left-Handed Threads Although rare, left-handed fasteners are

occasionally found on engine assemblies.

These fasteners will loosen when turned clockwise, and tighten

when turned counterclockwise.

Such fasteners are used to fasten parts to the ends of rotating

assemblies that turn counterclockwise, such as crankshafts and

camshafts.

They are also found on many older motorcycle engines. Some are

marked for easy identification, others are not.

Left-handed threads are also found inside some transaxles.

Continued


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Penetrating Oil Penetrating oil is a lightweight lubricant which

soaks into small crevices in the threads, by capillary action.

The chemical action of penetrating oils helps break up and

dissolve corrosion. The oil forms a layer of lubrication on the

threads to reduce friction.

Allow the oil to soak-in before removing nuts and bolts. To

increase effectiveness, tap on the bolt head or nut with a hammer,

or work the fastener back and forth with a wrench.

This weakens the bond of the corrosion and lets more of the

lubricant work down into the threads.

Continued


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Proper Tightening Proper tightening is critical for proper

clamping force and to prevent breakage.

A torque wrench allows the tech to exert a known amount of

torque to the fasteners. Rotating torque on a fastener does not

mean clamping force.

Up to 80% of torque is absorbed by thread friction. For accurate

tightening, two things must be performed:

Threads must be clean, and lubricated if service information

specifies that they be lubricated.

Always use a torque wrench to not ensure proper clampingforce, and ensure all fasteners are tightened the same.

Continued


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THREAD REPAIR INSERTS

Thread repair inserts are replace an original threaded holedamaged beyond use. The original hole is enlarged and a

threaded insert installed to restore threads to the original size.

Helical Inserts

A helical insert looks like a

small, stainless-steel spring.

Figure 825 Helical inserts look like small, coiledsprings. The outside is a thread to hold the coil in

the hole, and the inside threaded to fi t the fastener.

Continued


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Figure 826 The insert provides new, stock- size threads inside an oversize hole so that

the original fastener can be used.

To install a helical insert, a hole

is drilled to a specified over-

size, and then tapped using a

special tap.

The insert is then screwed into

the hole, as shown here.

The insert stays in the casting as

a permanent repair. Bolts can beremoved and replaced without

disturbing the insert.

Continued


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An advantage of a helical insert is that the original bolt can be

used because the internal threads are the same size.

Correctly installed, an insert is often stronger than original

threads, especially in aluminum castings. Some manufacturers,

such as BMW specify that threads be renewed using an insertif the head is removed and reinstalled.

Many high-performance engine rebuilders install inserts in blocks,

manifolds, and cylinder heads as a precaution.

Continued

One of the best known of the helical fasteners is the Helicoil ,

manufactured by Helicoil Products.


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Figure 827 Helicoil kits, available in a wide variety of sizes, contain everything needed

to repair a damaged hole back to its original size.

To install Helicoil inserts,

you need a thread repair kit.

The kit includes a drill bit,tap, installation mandrel,

and inserts.

Repair kits are available for

a wide variety of diameters

and pitch to fit both American

Standard and metric threads.

A simple kit contains tooling a specific thread size. Master kits

are available to cover a range of sizes. Continued


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51Continued

Installing an insert is similar to tapping new threads. A summary

of the procedures includes:

1. Select the Helicoil kit designed for the specific diameter and

thread pitch of the hole to be repaired.

2. Use the drill bit supplied with the kit. The drill size is also

specified on the Helicoil tap, to open up the hole to the

necessary diameter and depth.

3. Tap the hole with the Helicoil tap, being sure to lubricate

the tap. Turn it in slowly and rotate counterclockwiseoccasionally to break the chip that is formed.


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4. Thread an insert onto the installation mandrel until it seats

firmly. Apply a light coating of the recommended thread

locking compound to the external threads of the insert.

5. Use the mandrel to screw the insert into the tapped hole.

Once started, spring tension prevents the insert fromunscrewing. Stop when the top of the insert is 1/4 to 1/2

turn below the surface.

6. Remove the mandrel by unscrewing it from the insert, and

then use a small punch or needle-nose pliers to break off the

tang a the base of the insert. Never leave the tang in the bore.The finished thread is ready for use immediately.

Continued


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Threaded Inserts Are tubular, case-hardened, solid steel wall

pieces that threaded inside and outside. They return a damaged

hole to original size by replacing part of the surrounding casting.

The inner thread is sized to fit the original fastener of the hole to

be repaired. The outer thread design varies. These may be self-tapping threads installed in a blank hole, or machine threads

requiring a tapped hole.

Most inserts fit into three categories:

Self-tapping

Solid-bushingKey-locking

Continued


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Self-Tapping Inserts External threads of a self-tapping insert are

designed to cut their own way into a casting, eliminating the need

of running a tap down the hole. To install, follow this procedure:

1. Drill out damaged threads, opening the hole to proper size.

2. Select the proper insert and mandrel, usually available as a kit.3. Thread the insert onto the mandrel. Use a tap handle or wrench

to drive the insert into the hole. Because the insert cuts its own

path, it may require a considerable amount of force.4. Thread the insert in until the nut or flange of the mandrel

touches the workpiece. This is the depth stop to indicate the

insert is seated.

5. Hold the nut or flange with a wrench, and turn the mandrel out

of the insert. The threads are ready for immediate use.

Continued


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Figure 828 This solid-bushing insert is threaded on the outside, to grip the workpiece. The

inner threads match the desired bolt size.

Solid-Bushing Inserts

The external threads of solid-bushing inserts are ground to

a specific thread pitch.

You will have to run a tap

into the hole.

Continued


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Figure 829 A Timesert kit includes the dri ll (a), the recess cutter (b), a special tap (c),

the installer (d), and the Timesert threaded bushing (e).

(c) (d) (e)(b)(a)

Some inserts use a machine

thread so a standard tap canbe used; others have a unique

thread need a special tap.

The thread inserts come with

a matching installation kit.

Continued

To install threaded inserts, use

the procedure following.

1 D ill h d d h d h h l h


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Figure 830 Drill out the damaged

threads with the correct bit.

1. Drill out the damaged threads to open the hole to the proper

size. The drill bit supplied with the kit must be used as it is

properly sized to the tap.

2. Cut the recess in the top of the hole with the special tool, then

clean the hole with a brush or compressed air. Continued

3 U i l d il d i d h d h h l


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Figure 831 Use a special tap for

the insert

3. Use previously detailed tapping procedures to thread the hole.

Be sure to tap deep enough; the top of the insert must be flush

with the casting surface.

Continued

4 Th d th i t t th i t ll ti d i i th d i


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4. Thread the insert onto the installation driver, using the driver

to screw the insert into the hole. Some inserts require that a

thread-locking compound be applied; others go in dry.

5. Remove the installation driver, and the new threads are ready

for service with the original fastener.

K L ki I t Si il t lid b hi i t b t h ld i


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Key-Locking Insert Similar to solid-bushing inserts, but held in

place by small keys. After the insert has been installed, the keys

are driven into placeperpendicular to the threadsto keep theinsert from turning out.

A typical installation:

1. Drill out the damaged thread with the specified drill size.

2. Tap the drilled hole with the specified tap

Continued

3 Aft tti th d l ki d th i t th


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Figure 832 Put some thread-

locking compound on the insert.

3. After putting thread locking compound on the insert, use the

mandrel to screw the insert into the tapped hole until it is

slightly below the surface.

The keys act as a depth stop and prevents the insert from turning.

4 D i th k d i th d i li d ith th i t


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4. Drive the keys down using the driver supplied with the insert

kit. Be sure the keys are flush with the top of the insert.

Figure 833 Use the driver to drive the keys

down flush with the workpiece surface.

Figure 834 The insert and insert locks

should be below the workpiece.

SUMMARY


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SUMMARY

Continued

1. The most common type of fastener is a threaded one oftenreferred to as bolt. A nut or thread hole is used at the end of a

bolt to fasten two parts together.

2. The size of threaded fasteners includes the diameter, length,

and pitch of the threads, as well as the shape of the head of

the bolt.

3. Metric bolts are labeled with an M, and the diameter across

the threads is in millimeters followed by the distance between

the threads measured in millimeters, such as M8 1.5.

SUMMARY ( t )


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SUMMARY

4. Graded bolts are hardened and are capable of providing moreholding force than nongraded bolts

5. Many nuts are capable of remaining attached to the boltregardless of vibration. These types of nuts are often called

prevailing torque nuts.

6. Other commonly used fasteners in the automotive service

industry include sheet metal screws, snap rings and clips, door

panel clips, cotter pins, and rivets.

7. Threads can be repaired using a Helicoil or threaded insert.

(cont.)


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end


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start

OBJECTIVES


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Describe what tool is best to use for each job. Discuss how to safely use hand tools. Explain the difference between the brand name

(trade name) and the proper name for tools.

Explain how to maintain hand tools.

After studying Chapter 9, the reader shouldbe able to:

OBJECTIVES:

KEY TERMS:


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adjustable wrench aviation tin snips beam-typetorque wrench box-end wrench breaker bar (flex

handle)

cheater bar chisel clicker-type torque wrench cold

chisel close end combination wrench crowfoot

socket

dead-blow hammer diagonal (side-cut or dike) pliers

double-cut file drive size easy out extension

files fitting wrench flare-nut wrench flat-tip (straight

blade) screwdriver hacksaw locking pliers

KEY TERMS:

Continued

KEY TERMS: (cont )


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multi-groove adjustable pliers needle-nose pliers nutsplitter

offset left aviation snip offset right aviation snip open-end wrench punch ratchet removers

screwdriver seal driver seal puller single-cut file

slip-joint pliers snap-ring pliers socket socketadapter straight cut aviation snip stud removal tool

stud remover

tin snips torque wrench tube-nut wrench universal

joint utility knife VISE GRIPS water pump pliers

wrench

KEY TERMS: (cont.)

WRENCHES


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WRENCHES

Wrenches are the most used hand tool by service techs. Most areconstructed of forged alloy, usually chrome-vanadium steel.

The wrench is formed, hardened, tempered to reduce brittleness,

and then chrome plated. There are several types of wrenches.

Figure 91 A forged wrench after it has been forged but before the flashing, extra material

around the wrench has been removed.

Open-End Wrench An open-end wrench is used for bolts or


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Open-End Wrench An open-end wrench is used for bolts or

nuts that do not require a lot of torque. It can be easily placed on

a bolt or nut with an angle of 15 degrees.

The disadvantage of an open-end wrench is lack of torque that

can be applied, as the open jaws of the wrench only contact twoflat surfaces of the fastener.

An open-end wrench has two different sizes; one at each end.

Figure 92 A typical open-end wrench. The size is different on each end and notice that the

head is angled 15 degrees at each end.

Box-End Wrench A box-end wrench is also called a close-end


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Box-End Wrench A box-end wrench, is also called a close-end

wrench, has two different sizes; one at each end. It is placed over

the top of, and grips the points of the fastener.

Figure 93 A typical box-end wrench is able

to grip the bolt or nut at points completelyaround the fastener. Each end is a different

size.

A box-end wrench should be used to loosen or to tighten fasteners.

Figure 94 The end of a box-end

wrench is angled 15 degrees to allow

clearance for nearby objects or other

fasteners.

Continued

Most service technicians purchase combination wrenches which


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Most service technicians purchase combination wrenches, which

are open at one end and have the same size box on the other end.

Figure 95 A combination

wrench has an open end at oneend and a box end at the other.

A combination wrench allows the tech to loosen or tighten a

fastener using the box end of the wrench, and turn it around to

use the open end to increase the speed of rotating the fastener.

Continued

Adjustable Wrench An adjustable wrench is often used where


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Adjustable Wrench An adjustable wrench is often used where

the exact size wrench is not available or when a large nut, such as

a wheel spindle nut, needs to be rotated but not tightened.

An adjustable wrench should not be used to loosen or tighten

fasteners because the moveable jaws can loosen their grip on the

fastener, causing it to become rounded.

Figure 96 An adjustable wrench. Adjustable wrenches

are sized by the overall length of the wrench and not how

far the jaws open. Common sizes include 8, 10, and 12 inch.

Continued

Line Wrenches Called flare-nut wrenches fitting wrenches or


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Line Wrenches Calledflare nut wrenches, fitting wrenches, or

tube-nut wrenches. Designed to grip almost all the way around a

nut used to retain a fuel or refrigerant line, and yet able to beinstalled over the line.

Figure 97 The end of a typical line wrench, which shows that it is capable of grasping most

of the head of the fitting.

Safe Use of Wrenches Wrenches should be inspected before use


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Safe Use of Wrenches Wrenches should be inspected before use

to be sure they are not cracked, bent, or damaged. They should be

cleaned after use.

Always use the correct size of wrench for the fastener being

loosened or tightened to prevent the rounding of the fastener.

When attempting to loosen a fastener, pulldo not push a

wrench. If a wrench is pushed, your knuckles can be hurt when

forced into another object if the fastener breaks loose.

RATCHETS SOCKETS AND EXTENSIONS


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RATCHETS, SOCKETS AND EXTENSIONS

A socket fits over the fastener and grips the points and/or flats. Itis rotated (driven) using either a long bar called a breaker bar

(flex handle) or a ratchet.

Figure 98 A typical ratchet used to rotate a socket. A ratchet makes a ratcheting noise when

it is being rotated in the opposite direction from loosening or tightening. A knob or lever on the

ratchet allows the user to switch directions.

Figure 99 A typical flex handle used to rotate a socket, also called a breaker bar because


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it usually has a longer handle than a ratchet and therefore, can be used to apply more torque

to a fastener than a ratchet.

A ratchet turns the socket in only one direction and allows the

rotating of the ratchet handle back and forth in a narrow space.

Extensions anduniversal joints are used with sockets to allow

access to fasteners in restricted locations. Sockets are available

in various drive sizes, including 1/4-inch, 3/8-inch, and 1/2-inch.

Continued

Figure 910 The most commonly used socket drive sizes include 1 /4 -inch, 3 /8 -inch, and


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1 /2 -inch drive.

Many heavy-duty truck and/or industrial applications use 3/4 and

1-inch sizes. The drive size is the distance of each side of the

square drive. Sockets and ratchets of the same size are designed to

work together. Continued


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Figure 911 A six-pointsocket fits the head of the

bolt or nut on all sides. A

twelve-point socket can

round off the head of a

bolt or nut if a lot of force

is applied.

It is sometimes confusing which way to rotate a wrench or screwdriver,especially when the head of the fastener is pointing away from you. Tohelp visualize while looking at the fastener, say righty-tighty, lefty-loosey.

It is sometimes confusing which way to rotate a wrench or screwdriver,especially when the head of the fastener is pointing away from you. Tohelp visualize while looking at the fastener, say righty-tighty, lefty-loosey.

Right to Tighten

Crowfoot Sockets A crowfoot socket is a socket that is an open-


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p

end or line wrench to allow access to fasteners that cannot be

reached using a conventional wrench. Crowfoot sockets areavailable in the following categories:

Fractional inch open-end

Metric open-endFractional line

Metric line

Figure 912 A crowfoot socket is designed to reach fasteners using a ratchet or breaker bar

with an extension.

Torque Wrenches Socket turning handles designed to apply a


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q g g pp y

known force to the fastener are calledTorque wrenches. A

clicker-type torque wrench is set to the specified torque andclicks when the value has been reached.

When force is removed

from the handle, another

click is heard. The wrench

should be set back to zero

after use and check for

calibration regularly.

Figure 913 Using a torque wench to tighten

connecting rod nuts on an engine.

Continued

Figure 914 A beam-type torque wrench that displays the torque reading on the face of the dial.

Th b di l i d th b d f t hi h i i t i t th t f t


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The beam display is read as the beam defects, which is in proport ion to the amount of torque

applied to the fastener.

A beam-type torque wrench is used to measure torque. Instead ofpresetting the value, the actual torque is displayed on the dial as the

fastener is tightened. Beam-type wrenches are available in 1/4, 3/8,

and 1/2 inch drives, in English and metric units. Continued


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Figure 915 Torque wrench calibration

checker.

Torque wrenches should be checkedregularly. For example, Honda hasa torque wrench calibration setup ateach of their training centers. It isexpected that a torque wrench bechecked for accuracy before everyuse. Most experts recommend thattorque wrenches be checked andadjusted as needed at least everyyear and more often if possible.

Torque wrenches should be checkedregularly. For example, Honda has

a torque wrench calibration setup ateach of their training centers. It isexpected that a torque wrench bechecked for accuracy before every

use. Most experts recommend thattorque wrenches be checked andadjusted as needed at least everyyear and more often if possible.

Check Torque WrenchCalibration Regularly

Continued


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The unit for torque is expressed as a force times the distance (leverage)from the object. Therefore, the official unit for torque is lb-ft (pound-feet)or Newton-meters (a force times a distance). It is commonly expressed in

ft-lbs and even some torque wrenches are labeled with this unit.

The unit for torque is expressed as a force times the distance (leverage)from the object. Therefore, the official unit for torque is lb-ft (pound-feet)or Newton-meters (a force times a distance). It is commonly expressed in

ft-lbs and even some torque wrenches are labeled with this unit.

Is it Lb-Ft or Ft-Lb or Torque?

Misreading torque specs is easy to do but can have serious damagingresults. Specs for fasteners are commonly expressed lb-ft. Many smallerfasteners are tightened to specifications expressed in lb-in.

1 lb-ft =12 lb-in.If a fastener were accidentally tightened to 24 lb-ft instead of 24 lb-in., theactual torque applied will be 288 lb-in. instead of the specified 24 lb-in.The extra torque will likely break the fastener, but it could also warp or

distort the part being tightened. Always double-check the torque specs.

Misreading torque specs is easy to do but can have serious damagingresults. Specs for fasteners are commonly expressed lb-ft. Many smallerfasteners are tightened to specifications expressed in lb-in.

1 lb-ft =12 lb-in.If a fastener were accidentally tightened to 24 lb-ft instead of 24 lb-in., theactual torque applied will be 288 lb-in. instead of the specified 24 lb-in.The extra torque will likely break the fastener, but it could also warp or

distort the part being tightened. Always double-check the torque specs.

Double-Check the Specifications

Safe Use of Sockets and Ratchets Always use the proper size


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y p p

socket that correctly fits the bolt or nut. All sockets and ratchets

should be cleaned after use before being placed back into thetoolbox. Sockets are available in short and deep well designs.

Select the appropriate drive size.

For small work, such as on thedash, select a 1/4-inch drive. For

most general work, use a 3/8.

For suspension, steering and other

large fasteners, use a 1/2-inch

drive.

When loosening, pull toward

yourself.

Figure 916 Deep sockets allow access to

the nut that has a stud plus other locations

needing great depth, such as spark plugs.

Use Socket Adapters with Caution


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Socket adapters are available and can be used for different drive size

sockets on a ratchet. Combinations include:

Using a larger drive ratchet or breaker bar on a smaller size socket can

cause the application of too much force to the socket, which could crackor shatter. Using a smaller size drive tool on a larger socket will usuallynot cause any harm, but would greatly reduce the amount of torque thatcan be applied to the bolt or nut.

Socket adapters are available and can be used for different drive size

sockets on a ratchet. Combinations include:

Using a larger drive ratchet or breaker bar on a smaller size socket can

cause the application of too much force to the socket, which could crackor shatter. Using a smaller size drive tool on a larger socket will usuallynot cause any harm, but would greatly reduce the amount of torque thatcan be applied to the bolt or nut.

1 /4 -inch drive 3 /8 -inch sockets




Avoid Using Cheater Bars


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Whenever a fastener is difficult to remove, some technicians will insert the

handle of a ratchet or a breaker bar into a length of steel pipe. The extralength of the pipe allows the technician to exert more torque than can beapplied using the drive handle alone. However, the extra torque can easilyoverload the socket and ratchet, causing them to break or shatter, which

could cause personal injury.

Whenever a fastener is difficult to remove, some technicians will insert the

handle of a ratchet or a breaker bar into a length of steel pipe. The extralength of the pipe allows the technician to exert more torque than can beapplied using the drive handle alone. However, the extra torque can easilyoverload the socket and ratchet, causing them to break or shatter, which

could cause personal injury.

SCREWDRIVERS


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Many smaller fasteners are removed and installed by using ascrew-driver, available in many sizes and tip shapes.

The most commonly used iscalled a flat tip orstraight

blade.

Flat-tip screwdrivers are sized

by the width of the blade.

This width should match the

width of the slot in the screw.Figure 917 A flat-tip (straight blade)

screwdriver. The width of the blade should

match the width of the slot in the fastener.

Continued

CAUTION: Do not use a screwdriver as a pry tool or as a chisel. Always

CAUTION: Do not use a screwdriver as a pry tool or as a chisel. Always


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Another type of commonly used screwdriver is named for Henry

F. Phillips, who invented the crosshead screw in 1934. Due to the

shape of the screw and screwdriver, a Phillips screw can be drivenwith more torque than a slotted screw.

A Phillips head screwdriver is specified by the length of the

handle and size of the point at the tip.

A #1 tip has a sharp point, a #2 the most commonly used. A #3 tip

is blunt and used for larger sizes of Phillips head fasteners.

Both straight and Phillips screwdrivers are available with a short

blade and handle for access to fasteners with limited room.

use the proper tool for each application.use the proper tool for each application.

Both straight and Phillips screwdrivers are available with a short


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Figure 918 Two stubby screwdrivers that are used to access screws that have limited space

above. A straight blade is on top and a #2 Phill ips screwdriver is on the bottom.

blade and handle for access to fasteners with limited room.

Offset Screwdrivers Are used in places where a conventional


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screwdriver cannot fit. An offset is bent at the ends and is used

similar to a wrench. Most have a straight blade at one end and aPhillips end the other.

Figure 919 An offset screwdriver is used to install or remove fasteners that do not have

enough space above to use a conventional screwdriver.

Impact Screwdriver Is is used to break loose or tighten a screw.


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A hammer is used to strike the end after the screwdriver holder is

placed in the head of the screw and rotated the desired direction.

The force from the blow does

two things:

It applies a force downward

holding screwdriver tip in theslot and also applies a twisting

force to loosen (or tighten) the

screw.

Figure 920 An impact screwdriver used to

remove slotted or Phillips head fasteners that

cannot be broken loose using a standard

screwdriver.Continued


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A Canadian named P. L. Robertson invented the Robertson screw andscrewdriver in 1908, which uses a square-shaped tip with a slight taper.The Robertson screw-driver uses color-coded handles because different

size screws required different tip sizes. The color and sizes include:

The Robertson screws are rarely found in the United States but arecommon in Canada.

A Canadian named P. L. Robertson invented the Robertson screw andscrewdriver in 1908, which uses a square-shaped tip with a slight taper.The Robertson screw-driver uses color-coded handles because different

size screws required different tip sizes. The color and sizes include:

The Robertson screws are rarely found in the United States but arecommon in Canada.

What is a Robertson Screwdriver?

Orange(#00) Number 1 and 2 screws

Yellow (#0) Number 3 and 4 screws

Green (#1) Number 5, 6, and 7 screwsRed (#2) Number 8, 9, and 10 screws

Black (#3) Number 12 and larger screws

Continued

Safe Use of Screwdrivers Always use the proper type and size


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screwdriver that matches the fastener.

Try to avoid pressing down on a screwdriver because if it slips,

the screwdriver tip could go into your hand, causing serious

personal injury.

All screwdrivers should be cleaned after use.

Do not use a screwdriver as a pry bar; always use the correct tool

for the job.

HAMMERS AND MALLETS


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Hammers And mallets are used to force objects together or apart.The shape of the back part of the hammer head (called the peen)

usually determines the name.

For example, a ball-peen hammer has a rounded end like a ball

and it is used to straighten oil pans and valve covers, using the

hammer head, and for shaping metal, using the ball peen.

Figure 921A typical ball-peen hammer.

Continued

Mallets Are a type of hammer with a large striking surface,


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which allows the tech to exert force over a larger area.

This helps avoid damage to parts or components.

Mallets are made from a variety of materials including rubber,plastic, or wood.

Figure 922 A rubber mallet used to deliver a force to an object without harming the surface.

A shot-filled plastic hammer is called a dead-blow hammer. The

ll l d b ll ( h ) i id l i h d b i f h


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A hammer is usually sized by the weight of the head of the hammer

and the length of the handle. For example, a commonly used ball-

peen hammer has an 8-ounce head with an 11-inch handle.

small lead balls (shot) inside a plastic head prevent bouncing of the

hammer off of the object when struck.

Figure 923 A dead-blow hammer

that was left outside in f reezing

weather. The plastic covering was

damaged, which destroyed this

hammer. The lead shot is encased

in the metal housing and thencovered.

NOTE: A claw hammer has a claw used to remove nails and is not used for

automotive service

NOTE: A claw hammer has a claw used to remove nails and is not used for

automotive service


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automotive service.automotive service.

Safe Use of Hammers and Mallets All mallets and hammers

should be cleaned after use and not exposed to extreme

temperatures.

Never use a hammer or mallet that is damaged in any way.

Always use caution to avoid doing damage to components and

surrounding areas.

PLIERS


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Slip-Joint Pliers Pliers are capable of holding, twisting, bending,and cutting. They are an extremely useful classification of tools.

Common household pliers are calledslip-joint pliers.

Figure 924 Typical slip-joint pliers, which

are also common household pl iers. The slipjoint allows the jaws to be opened to two

different settings.

There are two different positions where the junction of the handles

meet to achieve a range of sizes of objects that can be gripped.

MultiGroove Adjustable Pliers For gripping larger objects,

i t f lti dj t bl li i


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using a set ofmultigroove adjustable pliers is common.

Originally designed to remove various size nuts holding rope sealsused in water pumps, the name water pump pliers is also used.

Figure 925 Multigroove adjustable pliers are known by many names, including the trade name

Channel Locks.

Linesmans Pliers Are specifically designed for cutting, bending,

d t i ti i Whil l d b t ti k


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Figure 926 A linesmans pliers are very useful because they can help perform many automotive

service jobs.

and twisting wire. While commonly used by construction workers

and electricians, they are very useful tools for the service tech whodeals with wiring.

The center parts of

the jaws are designed

to grasp round objects

such as pipe or tubingwithout slipping.

Diagonal Pliers Are designed for cutting only. The jaws are set at

l t k it i t t i Di l li l


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an angle to make it easier to cut wires. Diagonal pliers are also

calledside cut ordike.

Figure 927 Diagonal-cut pliers are another common tool that has many names.

Needle-Nose Pliers Designed to grip small objects or those in

ti ht l ti dl li h l i t d j


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tight locations, needle-nose pliers have long, pointed jaws.

Most have a wire cutter locat

Documents

03.Tools,Shop Equipment and Measuring