TM-43-0106 - TECHNICAL MANUAL ENGINEERING SERIES FOR AIRCRAFT REPAIR AEROSPACE METALS - GENERAL DATA AND USAGE FACTORS

8/17/2019 TM-43-0106 - TECHNICAL MANUAL ENGINEERING SERIES FOR AIRCRAFT REPAIR AEROSPACE METALS - GENERAL D…

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TO 1-1A

NAVAIR 01-1A

TM 43-010

TECHNICAL MANUAL

ENGINEERING SERIES

FOR AIRCRAFT REPAIR

AEROSPACE METALS -

GENERAL DATA

AND USAGE FACTORS

F09603-99-D-0382

DISTRIBUTION STATEMENT - Approved for public release; distribution is unlimited. Other requests for this document shall be referred to

MSUG/GBMUDE, Robins AFB, GA 31098. Questions concerning technical content shall be referred to 542 SEVSG/GBZR, Robins AFB, GA 31

Published Under Authority of the Secretary of the Air Force and by Direction of the Chief of the Naval Air Systems Command.

26 FEBRUARY 1999 CHANGE 5 - 27 JUNE 20

BASIC AND ALL CHANGES HAVE BEEN MERGED TO MAKE THIS A COMPLETE PUBLICATION


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NOTE: The portion of the text affected by the changes is indicated by a vertical line inthe margins of the page. Changes to illustrations are indicated by miniaturepointing hands. Changes to wiring diagrams are indicated by miniature point-ing hands or by shaded areas. A vertical line running the length of a figure inthe outer margin of the page indicates that the figure is being added.

INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES.LIST OF EFFECTIVE PAGES

*Zero in this column indicates an original page.

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Dates of issue for original and changed pages are:

TOTAL NUMBER OF PAGES IN THIS PUBLICATION IS 288, CONSISTING OF THE FOLLOWING:

Original . . . . . . . . . . . . . 0 . . . . . . . . . 26 February 1999Change. . . . . . . . . . . . . . 1 . . . . . . . . . . . . .25 June 2001Change. . . . . . . . . . . . . . 2 . . . . . . . . . . .1 October 2001

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Title . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

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2-3 - 2-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . 02-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-9 - 2-12 . . . . . . . . . . . . . . . . . . . . . . . . . . 02-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-14 - 2-26 . . . . . . . . . . . . . . . . . . . . . . . . . 02-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

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5-5 - 5-6 . . . . . . . . . . . . . . . . . . . . . . . . . . .45-7 - 5-11. . . . . . . . . . . . . . . . . . . . . . . . . . .05-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25-13 - 5-14 Deleted . . . . . . . . . . . . . . . . . . .15-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15-16 Blank. . . . . . . . . . . . . . . . . . . . . . . . . .15-17 - 5-19 . . . . . . . . . . . . . . . . . . . . . . . . .05-20 Blank. . . . . . . . . . . . . . . . . . . . . . . . . .06-1 - 6-10 . . . . . . . . . . . . . . . . . . . . . . . . . .06-11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .06-13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46-14 Blank. . . . . . . . . . . . . . . . . . . . . . . . . .07-1 - 7-5 . . . . . . . . . . . . . . . . . . . . . . . . . . .07-6 - 7-10 . . . . . . . . . . . . . . . . . . . . . . . . . .17-11 - 7-15. . . . . . . . . . . . . . . . . . . . . . . . . .07-16 Blank. . . . . . . . . . . . . . . . . . . . . . . . . .0

8-1 - 8-14 . . . . . . . . . . . . . . . . . . . . . . . . . .09-1 - 9-12 . . . . . . . . . . . . . . . . . . . . . . . . . .0A-1 - A-24. . . . . . . . . . . . . . . . . . . . . . . . . .0Glossary 1 - Glossary 10. . . . . . . . . . . . . . .0

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TABLE OF CONTENTS

Section Page Section Page

I INTRODUCTION................................................ ..... 1-1 2-199 Deleted

1-1 PURPOSE ............................................. 1-1 2-200 Deleted

2-201 DeletedII FERROUS (STEEL) ALLOYS................................. 2-1

2-202 Deleted2-1 Classification ........................................ 2-1

2-203 Deleted2-2 SAE Numbering System ...................... 2-1

2-216 Deleted2-4 Carbon Steels........................................ 2-1

2-234 Fabrication of Ferrous2-7 Nickel Steels ......................................... 2-2

Alloys..............................................2-1212-8 Chromium Steels .................................. 2-2

2-292 Steel Surface Finishes...................... 2-1302-9 Chromium - Nickel Steels.................... 2-2

2-11 Chrome - Vanadium Steels.................. 2-3 III ALUMINUM ALLOYS............................................. 3-1

2-12 Chrome - Molybdenum 3-1 Classification ........................................ 3-1

Steels ..................................................2-3 3-4 Commercial and Military

2-13 Principles of Heat Treat- Designations ......................................3-1

ment of Steels ....................................2-3 3-8 Mechanical Properties.......................... 3-22-14 Hardening ............................................. 2-3 3-16 Physical Properties............................. 3-18

2-19 Quenching Procedure ........................... 2-4 3-17 Heat Treatment of Alumi-

2-26 Tempering (Drawing) ........................... 2-4 num Alloys .......................................3-18

2-29 Normalizing.................................... ....... 2-5 3-51 Heat Treatment.................................. 3-24

2-30 Case Hardening.................................... 2-5 3-56 Heat Treating Equipment.................. 3-24

2-35 Carburizing ........................................... 2-6 3-70 Fabrication.......................................... 3-28

2-41 Cyaniding.............................................. 2-7 3-73 Forming Sheet Metal.......................... 3-28

2-42 Nitriding................................................ 2-7 3-96 Deleted

2-43 Heat Treating Equipment.................... 2-7 3-97 Deleted

2-48 Heat Control, Furnace Tem- 3-118 Deleted

peratures Survey and 3-123 Deleted

Temperature Measuring 3-131 Deleted

Equipment................................... .......2-8 3-145 Deleted

2-53 Furnace Control Instru- 3-154 Deleted

ments Accuracy..................................2-8 3-175 Machining..................................... ....... 3-45

2-55 Salt Bath Control ............................... 2-10 3-179 Cutting Tools for Machin-2-58 Quenching Tanks and ing Aluminum..................................3-45

Liquids........................................ ......2-10 3-180 Turning......................................... ....... 3-46

2-60 Heat Treating Procedures.................. 2-10 3-183 Milling-Aluminum.............................. 3-46

2-68 Hardness Testing................................ 2-11 3-189 Shaping and Planing.......................... 3-49

2-73 Specification Cross 3-195 Tapping......................................... ....... 3-56

Reference.................................... ......2-11 3-198 Filing ................................................... 3-56

2-74 General Heat Treating 3-202 Reaming .............................................. 3-57

Temperatures, Composi- 3-204 Sawing................................................. 3-57

tion (Chemical) and 3-210 Grinding.............................................. 3-58

Characteristics of Vari- 3-216 Polishing....................................... ....... 3-58

ous Steel and Steel Alloy................2-35 3-218 Roughing ............................................. 3-58

2-75 Machining of Steels 3-219 Greasing or Oiling.............................. 3-58

(General) ..........................................2-60 3-221 Buffing ................................................ 3-59

2-81 Machining Corrosion Re- 3-223 Hardness Testing................................ 3-59

sisting Steel .....................................2-65 3-226 Non-Destructive2-117 Deleted Testing/Inspection ...........................3-59

2-128 Deleted 3-228 Anodizing Process for In-

2-131 Deleted spection of Aluminum

2-135 Deleted Alloy Parts .......................................3-59

2-147 Deleted 3-231 Aluminum Alloy Effects on

2-152 Deleted Scratches on Clad Alu-

2-168 Deleted minum Alloy ....................................3-59

2-184 Deleted 3-233 Allowable Defects................................ 3-59

2-186 Deleted 3-234 Harmful Scratches.............................. 3-60

2-195 Deleted

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TABLE OF CONTENTS - Continued


3-241 Disposition of Scratches 5-39 Deleted

Sheets/Parts.....................................3-60 5-40 Deleted

3-242 Cleaning of Aluminum Al- 5-42 Deleted

loy Sheet (Stock)..............................3-60 5-43 Deleted

5-45 DeletedIV MA GNESIUM ALLOYS .......................................... 4-1

5-47 Soldering ............................................. 5-154-1 Classification ........................................ 4-1

5-48 Riveting ............................................... 5-154-4 Definitions............................................. 4-1

5-51 Machining and Grinding.................... 5-174-13 Safety Requirements for

5-52 Machining..................................... ....... 5-17Handling and Fabrication

5-54 Turning......................................... ....... 5-17of Magnesium Alloys.........................4-2

5-57 Milling ................................................. 5-174-19 Safety Precautions for All

5-63 Drilling................................................ 5-17 Alloys (Including Fire

5-66 Tapping......................................... ....... 5-19Hazards).............................................4-3

5-69 Reaming .............................................. 5-194-22 Grinding and Polishing 5-70 Grinding.............................................. 5-19Safety Practices...............................4-14

4-24 Deleted VI COPPER AND COPPER BASE

4-25 Heat Treating Safety ALLOYS.................................................................... 6-1

Practices...........................................4-15 6-1 Copper and Copper Base

4-26 Identification ...................................... 4-16 Alloys..................................................6-1

4-29 Heat Treating Magnesium 6-3 Copper Alloying Elements ................... 6-1

Alloys -(General)..............................4-16 6-5 Heat Treatment and Hot

4-45 Alloy General Characteris- Working Temperature of

tic Information.................................4-19 Copper Alloys.....................................6-1

4-47 Deleted 6-7 Stress Relief of Copper

4-77 Deleted Alloys..................................................6-1

4-78 Deleted 6-9 Machining Copper and Cop-

4-79 Deleted per Alloys ...........................................6-1

4-82 Deleted 6-10 Wrought - Copper - Berylli-

4-93 Deleted um Alloys ...........................................6-16-12 Heat Treating Procedures

V TITANIUM AND TITANIUM ALLOYS................. 5-1and Equipment

5-1 Classification ........................................ 5-1Requirements...................................6-10

5-4 General.................................................. 5-16-15 Solution - Heat Treatment

5-5 Military and CommercialCopper Beryllium ............................6-11

Designations ......................................5-16-17 Precipitation or Age

5-6 Physical Properties............................... 5-1Hardening........................................6-11

5-7 Mechanical Properties.......................... 5-1

5-10 Methods of Identification..................... 5-1 VII TOOL STEELS......................................................... 7-1

5-11 Hardness Testing.................................. 5-1 7-1 General.................................................. 7-1

5-12 Tensile Testing ..................................... 5-1 7-4 Alloying Elements in Tool

5-13 Non-Destructive Testing...................... 5-1 Steels ..................................................7-1

5-14 Fire Damage ......................................... 5-6 7-5 Specifications ........................................ 7-1

5-15 Heat Treatment - (General)................. 5-6 7-6 Class Designations ............................... 7-5

5-22 Hydrogen Embrittlement ..................... 5-8 7-7 Applications of Tool Steels................... 7-5

5-25 Fabrication.......................................... 5-11 7-9 Selection of Material for a5-26 Forming Sheet Metal - Cutting Tool .......................................7-5

(General) ..........................................5-11 7-16 Heat Treat Data ................................... 7-6

5-28 Draw Forming..................................... 5-11 7-18 Distortion in Tool Steels ...................... 7-6

5-29 Hydraulic Press Forming................... 5-11 7-19 Deleted

5-32 Stretch Forming.................................. 5-11 7-21 Deleted

5-33 Drop - Hammer Forming ................... 5-11 7-22 Deleted

5-34 Joggling ............................................... 5-12 7-23 Deleted

5-35 Blanking and Shearing ...................... 5-12 VIII TESTING AND INSPECTION, HARD-

5-37 DeletedNESS TESTING....................................................... 8-1

5-38 Deleted

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TABLE OF CONTENTS - Continued


8-1 General.................................................. 8-1 IX HEAT TREATMENT............................................... 9-1

8-3 Methods of Hardness 9-1 General.................................................. 9-1

Testing.......................................... ......8-1 9-9 Special Heat Treatment

8-5 Brinell Hardness Test .......................... 8-1 Information........................................9-1

8-8 Rockwell Hardness Test....................... 8-1 9-11 Tint Test for Determining

8-15 Vickers Pyramid Hardness Coating Removal from

Test.....................................................8-4 Nickel Base and Cobalt Base

8-18 Shore Scleroscope Hardness Alloys..................................................9-1

Test.....................................................8-8 9-13 Titanium Alloy Parts............................ 9-3

8-20 Testing with the 9-16 Solution, Stabilization, or

Scleroscope .........................................8-9 Precipitation Heat Treatment ..........9-3

8-21 Tensile Testing ..................................... 8-9 9-38 Stress-Relief After Welding................. 9-8

8-22 Decarburization 9-59 Local Stress-Relief .............................. 9-1

Measurement .....................................8-9 9-68 Description of Methods ...................... 9-18-24 Hardness Method................................ 8-10 A Supplemental Data ..................................................A-1

8-27 Nondestructive Inspection

Methods............................................8-14 Glossary .............................................................. .GLS 18-33 Chemical Analysis .............................. 8-14

8-34 Spectrochemical Analysis................... 8-14

LIST OF ILLUSTRATIONS

Figure Title Page Figure Title Page

2-1 Number and Distribution of 4-2 Deleted

Thermocouples...................................... ......2-9 4-3 Deleted2-2 Deleted 4-4 Deleted

2-3 Deleted 8-1 Brinell Hardness Tester................................ 8-4

2-4 Stretch Forming......................................... 2-127 8-2 Rockwell Hardness Tester ............................ 8-5

2-5 Surface Roughness .................................... 2-135 8-3 Attachments for Rockwell Tester................. 8-6

3-1 Head to Alloy Identification 8-4 Vickers Pyramid Hardness Tester ............... 8-7

Method ......................................................3-20 8-5 Standard Pyramid Diamond

3-2 Drill Designs and Recommended Indentor.......................................................8-8

Cutting Angles..........................................3-55 8-6 Shore Scleroscope .......................................... 8-8

4-1 Typical Dust Collectors for 8-7 Test Specimens............................................ 8-1

Magnesium......................................... .......4-22

LIST OF TABLES

Number Title Page Number Title Page

2-1 Soaking Periods for Hardening 2-4 Machinability Rating of Various

Normalizing and Annealing Metals........................................................2-61

(Plain Carbon Steel).................................2-10 2-5 Conversion of Surface Feet Per

2-2 Specification Cross Reference .................... 2-12 Minute (SFM) to Revolutions

2-3 Cutting Speeds and Feeds for Per Minute (RPM)....................................2-63

SAE 1112 Using Standard 2-6 Tool Correction Chart ................................. 2-64

High Speed Tools .....................................2-61

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LIST OF TABLES - Continued


2-7 General Machining Comparison 3-7 Heat Treating (Soaking)

of Corrosion Resisting Steel to Temperatures ...........................................3-17

Free Machining Screw Stock 3-8 Soaking Time for Solution Heat

B1112 ........................................................2-65 Treatment of All Wrought

2-8 Suggested Cutting Speeds and Products ....................................................3-23

Feeds .........................................................2-66 3-9 Soaking Time for Solution

2-9 Tool Angles - Turning................................. 2-68 Treatment of Cast Alloys.........................3-23

2-10 Suggested Milling Cutting 3-10 Recommended Maximum

Speeds and Feeds.....................................2-69 Quench Delay, Wrought Al-

2-11 Suggested Tool Angles - Milling................. 2-70 loys (For Immersion Type

2-12 Drilling Speeds for Corrosion Quenching)................................................3-24

Resisting Steel..........................................2-70 3-11 Precipitation (Aging) Treating

2-13 Tapping Allowances (Holes Size Temperatures, Times and

to Screw Size) ...........................................2-71 Conditions.................................................3-252-14 Deleted 3-12 Reheat Treatment of Alclad

2-15 Deleted Alloys.........................................................3-27

2-16 Deleted 3-13 Cold Bend Radii (Inside) for

2-17 Deleted General Applications................................3-29

2-18 Deleted 3-14 Maximum Accumulative Reheat

2-19 Deleted Times for Hot Forming Heat

2-20 Deleted Treatable Alloys at Different

2-21 Deleted Temperatures ...........................................3-32

2-22 Deleted 3-15 Deleted

2-23 Deleted 3-16 Deleted

2-24 Deleted 3-17 General Rivet (Alum) Identifica-

2-25 Deleted tion Chart .................................................3-42

2-26 Deleted 3-18 General Aluminum Rivet Selec-

2-27 Deleted tion Chart (Rivet Alloy vs As-

2-28 Deleted sembly Alloy) ............................................3-45

2-29 Deleted 3-19 Shear Strength of Protruding 2-30 Deleted and Flush Head Aluminum

2-31 Deleted Alloy Rivets, Inch Pounds .......................3-47

2-32 Deleted 3-20 Bearing Properties, Typical, of

2-33 Deleted Aluminum Alloy Plates and

2-34 Cold Bend Radii (Inside) Car- Shapes.......................................................3-48

bon/Low Alloy Steels..............................2-128 3-21 Standard Rivet Hole Sizes with

2-35 Cold Bend Radii (Inside) Cor- Corresponding Shear and

rosion Resistant Steel Alloys.................2-128 Bearing Areas for Cold Driven

2-36 Forging Temperature Ranges Aluminum Alloy Rivets............................3-50

for Corrosion Resistant Steel ................2-128 3-22 Turning Speeds and Feeds ......................... 3-51

2-37 Galvanic Series of Metals and 3-23 Tool Angles - Turning................................. 3-52

Alloys.......................................................2-134 3-24 Milling - Speeds and Feeds ........................ 3-52

2-38 Surface Roughness and Lay 3-25 Tool Angles - Milling................................... 3-53

Symbols...................................................2-136 3-26 Shaping and Planing - Speeds

3-1 Designations for Alloy Groups ..................... 3-1 and Feeds..................................................3-543-2 Aluminum Alloy Designation and 3-27 Shaping Tool Angles ................................... 3-54

Conversions to 4 Digit System..................3-1 3-28 Thread Constant for Various

3-3 Federal and Military Standard Thread Forms ..........................3-56

Specifications..............................................3-3 4-1 Cross-Reference, Alloy Designa-

3-4 Chemical Composition Nominal tions to Specifications................................4-3

and General Use Data 1/ ...........................3-9 4-2 Alloy Designation

3-5 Mechanical Properties - Typical................. 3-14 Cross-Reference..........................................4-6

3-6 Physical Properties - Standard 4-3 Chemical Properties of Magnesi-

Alloys.........................................................3-16 um Alloys....................................................4-7

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4-4 Mechanical Properties Magnesi- 6-2 Hot Working and Annealing

um Extrusions and Forgings at Temperatures for Copper and

Room Temperature - Typical.....................4-9 Wrought Copper Alloys..............................6-9

4-5 Mechanical Properties Magnesi- 6-3 Typical Stress-Relief Treat-

um Alloy Sheet and Plate at ments for Certain Copper Alloys ............6-11

Room Temperature - Typical...................4-11 6-4 Standard Machinability Rating

4-6 Mechanical Properties of Mag- of Copper Alloys .......................................6-12

nesium Alloy Castings at 6-5 Typical Engineering Properties.................. 6-13

Room Temperatures.................................4-12 6-6 Age Hardening

4-7 Physical Properties - Magnesi- Time-Temperature Conditions

um Alloy @ 68oF......................................4-13 and Material Temper -

4-8 Solution Heat Treating Temper- Designations .............................................6-13

atures and Holding Times.......................4-18 7-1 Tool Steel Specifications............................... 7-2

4-9 Artificial Aging (Precipitation 7-2 Chemical Composition, Tool Steel................ 7-3Treatment)................................................4-19 7-3 Tool Steel Selection....................................... 7-5

4-10 Deleted 7-4 Tool Steel Hardening and Tem-

4-11 Deleted pering Temperatures .................................7-5

4-12 Deleted 7-5 Forging, Normalizing and An-

4-13 Deleted nealing Treatments of Tool and

4-14 Deleted Die Steels....................................................7-7

4-15 Deleted 7-6 Thermal Treatment for Harden-

4-16 Deleted ing and Tempering Tool Steel

4-17 Deleted - General ...................................................7-11

4-18 Deleted 7-7 Comparison of Tool Steel

4-19 Deleted Properties..................................................7-14

4-20 Deleted 8-1 Hardness Conversion Chart ......................... 8-3

4-21 Deleted 8-2 Rockwell Scales, Loads and Pre-

4-22 Deleted fix Letters .................................................8-10

4-23 Deleted 8-3 Approximate Hardness - Tensile

4-24 Deleted Strength Relationship of Car-4-25 Deleted bon and Low Alloy Steels ........................8-12

4-26 Deleted 9-1 Typical Heat Treatment

4-27 Deleted Application..................................................9-1

4-28 Deleted 9-2 Cross-Index for Solution, Stabili-

4-29 Deleted zation or Precipitation Heat

4-30 Deleted Treatments .................................................9-4

4-31 Deleted 9-3 Cross-Index for Stress-Relief

5-1 Specification Cross Reference Ti- Heat Treatments ........................................9-9

tanium Alloy...............................................5-2 A-1 Chemical Symbols .........................................A-1

5-2 Nominal Mechanical Properties A-2 Decimal Equivalents.....................................A-2

at Room Temperature................................5-7 A-3 Engineering Conversion Factors ..................A-6

5-3 Heat Treat, Stress Relief and An- A-4 Table of Weights - Aluminum

nealing Temperatures and Times.............5-9 and Aluminum Alloy ................................. A-8

5-4 Recommended Minimum CCLD A-5 Table of Weights - Brass...............................A-9

Bend Radii ................................................5-12 A-6 Table of Weights - Bronze ..........................A-105-5 Deleted A-7 Table of Weights - Copper ..........................A-11

5-6 Turning Speeds for Titanium A-8 Table of Weights - Iron ...............................A-12

Alloys.........................................................5-18 A-9 Table of Weights - Lead ..............................A-12

5-7 Tool Angles for Alloys ................................. 5-18 A-10 Table of Weights - Magnesium

5-8 Speeds and Feeds for Milling ..................... 5-18 and Magnesium Alloy ............................. A-12

5-9 Angles for Tool Grinding ............................ 5-19 A-11 Table of Weights - Nickel Chro-

6-1 Chemical Composition by Trade mium Iron Alloy (Inconel) ...................... A-13

Name...........................................................6-2 A-12 Table of Weights - Nickel Cop-

per Alloy................................................... A-13

A-13 Table of Weights - Steel..............................A-13

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A-14 Table of Weights - Zinc ...............................A-16 A-18 Bend Set Back Chart ..................................A-21

A-15 Temperature Conversion Chart .................A-17 A-19 Comparative Table of Standard

A-16 Standard Bend Radii for 90o

Gages.................................................. ...... A-22

Cold Forming-Flat Sheet ........................ A-18 A-20 Melting Points Approximate.......................A-23

A-17 Metal Bending and Bend Radii

Bend Allowances Sheet Metal

Bend Allowances Per Degree

of Bend Aluminum Alloys....................... A-19

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SECTION I

INTRODUCTION

1-1. P U RP OS E. 1-4. The informa tion/instruction contained

herein ar e for genera l use. If a conf lict exists1-2. This is one of a series of technical or engi-betw een this technical ma nua l and t he specific

neering technical m an uals prepared to a ssist per-technical manual(s) or other approved data for a

sonnel engaged in the ma intenan ce and repair ofparticular w eapon, end i tem, equipment, etc., th e

Aerospace Weapon Systems and Supporting Equip-data applicable to the specific item(s) will govern

ment (AG E). Army P ersonnel: Wherever the textin a l l cases.

of this manual refers to other technical orders(T.O.’s) for support ing informat ion, refer to compa- 1-5. The use of ‘‘shal l ’’, ‘‘wi l l ’’, ‘‘should’’ andra ble Army documents. ‘‘ma y’’ in this t echnica l ma nua l is a s follow s:

1-3. Th is tech nica l m a nu a l pr ovid es pr ecise d a ta a . Wh en ever t he w or d ‘‘sh a ll’’ a ppea r s, it sh a lon speci f i c meta l s to ass is t in select ion , usage and be in terpreted to mean tha t the requirements a repr oces sin g for f a br ica t ion a n d r epa i r. I t in clu des b in din g.such data as specification cross reference;

b. The words ‘‘wil l ’’, ‘‘should’’ an d ‘‘ma y’’, shallapproved designa tion system for al loys and tem-

be interpreted a s nonma nda tory provisions.pers; temperatures and other controls for heattreat ments; mecha nical an d physical properties c. The word ‘‘wi l l ’’ is used to express declara-processing inst ructions for ba sic corrosion preven- tion of purpose.tion; forming char acteristics; a nd other informa -

d. The word ‘‘should’’ is used to express non-tion required for general aerospace weapon systemmandatory desired or preferred method ofrepair. P rocedures for genera l foundry practice,accomplishment.sand control , gat ing a nd risering of both ferrous

and non-ferrous castings may be obtained from e. The word ‘‘may’ ’ i s used to express ana va ilable commercia l ha ndbooks and /or publica - acceptable or suggested means of accomplishment.t ions. Due to the many ty pes, grades, deversif ied

1-6. D elet eduses and new developments of metal products, itma y not include al l dat a r equired in some 1-7. WELDING. In format ion on welding aero-instances and further study and citation of this spa ce meta ls is cont a ined in NAVAIR 01-1A-34,dat a w il l be required. If a requirement exists for T.O. 00-25-252, T.C. 9-238.informa tion not included, a request for assista nceshould be ma de to WR-ALC , LE M.

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SECTION II

FERROUS (STEEL) ALLOYS

2-1. C L AS S I F IC ATI ON .

TYP E OF S TE E L NU ME RALS2-2. S AE N U MB E R IN G S YS TE M. A n um er a l(AND DIGITS)index system is used to identify the compositions

of the SAE steels, which makes it possible to use Nickel-Chromium-Molybdenumnumerals t ha t a re partia lly descriptive of the com- Steelsposition of mat erial covered by such numbers. Thef irst digit indicates the ty pe to which the steel 1.80%nickel; 0.50 and 0.80%belongs; for exam ple ‘‘1’’ indicates a carbon steel; Chromium; 0.25% Molybdenum 43xx‘‘2’’ a nickel steel; and ‘‘3’’ a nickel chromium steel. 0.55%Nickel; 0.50 and 0.65%In the case of the simple alloy steels, the second Chromium; 0.20% Molybdenum 86xxdigit generally indicat es the a pproximat e percent- 0.55%Nickel; 0.50 Chromiumage of the predominant a lloying element. Usua lly 0.25% Molybdenum 87xxthe last t wo or three digits indicate the a pproxi- 3.25%Nickel; 1.20 Chromiummate average carbon content in ‘‘points’’ or hun- 0.12% Molybdenum 93xxdredt hs of 1 percent . Thus ‘‘2340’’ indicates anickel steel of approximately 3 percent nickel (3.25 Nickel-Molybdenum St eelsto 3.75) a nd 0.40 percent car bon (0.38 to 0.43). In 1.75 Percent Nickel; 0.25some instances, in order to avoid oonfusion, it has percent Molybdenum 46xxbeen found necessary to depart from this system of 3.50 Percent Nickel; 0.25identifying the approximate alloy composition of a percent Molybdenum 48xxsteel by va rying the second and third digits of thenumber. An insta nce of such depart ure is the Chromium S t eels 5xxxsteel num bers selected for several of t he corrosion Low C hromium 50xx--and heat resisting alloys. Medium C hromium 51xxx

H igh Chromium 52xxx2-3. The bas ic numerals for the var ious types ofCorrosion and HeatSAE steel are:Resist ing 514xx a nd

515xxTYP E OF S TE E L NU ME RALS

(AND DI G ITS)Chromium-Va na dium S teel 6xxx

0.80-1.00 percent Chromium,Ca rbon S t eels 1xxx0.10-0.15 Va na dium 61xxP la in Ca rbon 10xx

F ree Cut t ing (S crew S t ock) 11xxS ilicon Ma nga nese S teels 9xxx

A P ercent S ilicon 92xxMa nga nese S t eels 13xxLow Alloy , H igh Tensile 950B oron Intensif ied xxB xxNickel Chromium S t eels 3xxxLea ded S t eels xxLxx1.25 Percent Nickel; 0.65

percent Chromium 31xxC orrosion a nd H ea t Resist ing 303xx 2-4. CARB ON S TE E L S . S t eel con t a ining ca r -

bon in percentages ranging from 0.10 to 0.30 per-Molybdenum S t eels 4xxx cent is cla ssed a s low ca rbon st eel. The equiva lent

0.25 P ercent Molybdenum 40xx S AE numbers ra nge from 1010 t o 1030. S t eels ofthis gra de are used for th e man ufacture of art iclessuch a s safety w ire, certain nuts, cable bushing,etc. This steel in sheet form is used for seconda rystructural parts and clamps and in tubular formfor moderately stressed structura 1 parts .

2-5. Steel conta ining carbon in percentages rang-ing from 0.30 to 0.50 percent is classed as mediumcarbon steel. This steel is especially a da pta ble forma chining, forging, and where surface hardn ess is

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mportant. Certain rod ends, light forgings, and parts such as

Woodruff keys, are made from SAE 1035 steel.

2-6. Steel containing carbon in percentage ranging from 0.50

o 1.05 percent is classed as high carbon steel. The addition of

other elements in varying quantities adds to the hardness of

his steel. In the fully heat-treated condition it is very hard and

will withstand high shear and wear, but little deformation. Ithas limited use in aircraft construction. SAE 1095 in sheet

form is used for making flat springs and in wire form for

making coil springs.

2-7. NICKEL STEELS. The various nickel steels are pro-

duced by combinining nickel with carbon steel. Some benefits

derived from the use of nickel as an alloy in steel are as

follows:

a. Lowers the percentage of carbon that is necessary for

hardening. The lowering of the carbon content makes the steel

more ductile and less susceptible to uneven stress.

b. Lowers the critical temperature ranges (heating and

cooling) and permits the use of lower heating temperatures for

hardening.

c. Hardening of nickel alloy steels at moderate rates of

cooling has the advantage of lowering the temperature gradi-

ents, reducing internal stress/warpage and permits deeper/

more uniform hardening.

d. The low heat treating temperatures required, reduces the

danger of overheating, excessive grain growth and the conse-

quent development of brittleness.

e. The characteristics depth hardening from the addition of

nickel to steel as an alloy results in good mechanical proper-

ties after quenching and tempering. At a given strength

(except for very thin sections/parts) the nickel steels provide

greatly improve elastic properties, impact resistance and

toughness.

2-8. CHROMIUM STEELS. Chromium steel is high in

hardness, strength, and corrosion resistant properties. SAE

51335 steel is particularly adaptable for heat-treated forgings

which require greater toughness and strength than may be

obtained in plain carbon steel. It may be used for such articlesas the balls and rollers of anti-friction bearings.

2-9. CHROMIUM-NICKEL STEELS. Chromium and nickel

n various proportions mixed with steel form the chrome-

nickel steels. The general proportion is about two and one-half

imes as much nickel as chromium. For all ordinary steels in

his group the chromium content ranges from 0.45 to 1.25

percent, while the nickel content ranges from 1 to 2 percent.

Both nickel and chromium influence the properties of steel;

nickel toughens it, while chromium hardens it. Chrome-nickel

steel is used for machined and forged parts requiring strength,

ductility, toughness and shock resistance. Parts such as crank-

shafts and connecting rods are made of SAE 3140 steel.

2-10. Chrome-nickel steel containing approximately 18 per-

cent chromium and 8 percent nickel is known as corrosion-resistant steel. It is usually identified as aisi types 301, 302,

303, 304, 304L, 309, 316, 316L, 321, 347, 347F or Se, etc.,

however; the basic 18-8 chrome-nickel steel is type 302. The

other grades/types have been modified by changing or adding

alloying elements to that contained in the basic alloy. The

alloys are varied to obtain the required mechanical properties

for some specific purpose such as improving corrosion resis-

tance or forming machining, welding characteristics, etc. The

following are examples of variations:

a. 301-Chromium and Nickel (approximate 0.5 Nickel) is

lowered to increase response to cold working.

b. 302-Basic Type 18 Chromium 8 Nickel.

c. 303-Sulfur(s) or Selenium (se) added for improved

machining characteristics.

d. 304-Carbon (c) lowered to reduce susceptibility to car-

bide precipitation. This alloy is still subject to carbide pre-

ceipitation from exposure to temperatures 800-1500F range

and this shall be considered when it is selected for a specific

application.

e. 304L-Carbon (c) lowered for welding applications.

f. 309-Cr and Ni higher for additional corrosion and scale

resistance.

g. 316-Molybdenum (Mo) added to improve corrosion

resistance and strength.

h. 316L-C- lowered for welding applications.

i. 321-Titanium (Ti) added to reduce/avoid carbide precip-

itation (stabilized grade).

j. 347-Columbium (Cb), Tantalum (Ta)- Added to reduce/avoid carbide precipitation (stabilized grade).

k. 347F or Se - Sulfur (s) or Selenium (Se) added to

improve machinability.

The chrome-nickel steels are used for a variety of applications

on aircraft and missiles. In plate and sheet form it is used for

firewalls, surface skin,

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exhaus t st acks , hea ter duct s , gun we lls, ammuni- cool ing is slow , the ca rb ide par t icles a re rela t ive lyt ion chutes , clamps , hea t sh ields/def lector s , f a i r- coarse and few ; in th is condit ion the s tee l i s sof t .i ng , s t if f en er s, b ra ck et s , s h im s , et c. I n ba r a n d I f t h e cool in g i s r a pid, a s be q u en ch in g in oi l orr od it i s u sed t o f a br ica t e va r iou s f i t t in g s, bol t s, w a t e r, t he ca r b on pr ecipi ta t e s a s a clou d of ver ys tu ds , s cr ew s , n ut s, cou pl in gs , f la n ges , v a lv e f i ne ca r bi de pa r t icles , w h ich con dit ion is a s soci-s t em s/s ea t s , t u r n-b uck les , et c. I n w ir e f or m it is a t e d w i t h h ig h h a r d nes s of t h e s t eel .used for safety wire, cable, rivets, hinge pins,

2-15. At elevated temperatures, the iron matrixscreens/screening a nd other miscellaneous it ems.exists in a form called ‘‘austenite’’ w hich is capa bleof dissolving ca rbon in solid solution. At ordina ry2-11. C HROME -VAN AD I U M S TE E L S . Th etemperatures th e iron exists as ‘‘ferrite’’, in wh ichvan adium content of this steel is a pproximat elycarbon is relatively insoluble and precipitates; as0.18 percent and the chromium content approxi-described in the preceding paragraph, in the formma tely 1.00 percent. Ch rome-va na dium steelsof carbide part icles. The temperat ure at wh ichwhen heat-treated have excellent properties suchthis chan ge from a ustenite to ferrite begins toas strength, toughness, and resistance to wear andoccur on cooling is called the ‘‘upper critical tem-fatigue. A special grade of this steel in sheet formperature ’’ of the steel, and varies wit h th e carboncan be cold-formed int o intr icate sha pes. It ca n becontent; up to approximately 0.85 percent carbon,folded and f lat tened without signs of breaking orthe upper crit ical temperat ure is lowered w ithfailure. Chrome-van adium steel wit h mediumincreasing carbon content ; from 0.85 to 1.70 per-high carbon content (SAE 6150) is used to makecent carbon the upper critical temperature issprings. Chrome-vana dium steel wit h high carbon

raised with increasing car bon content. St eel tha tcontent (SAE 6195) is used for ball a nd rollerha s been heated t o its upper crit ical point w illbearings.harden completely if rapidly quenched; however, in

2-12. C HROME - MOLYB DENU M STEE LS. practice it is necessary to exceed this temperatureMolybdenum in small percentage is used in combi- by/from a pproxima tely 28o to 56oC (50o to 100oF)nation with chromium to form chrome-molybde- to insure thorough heating of the inside of thenum st eel; this steel has importa nt applicat ions in piece. If the upper critica l temperat ure isaircraf t . Molybdenum is a strong alloying element, exceeded too much, an unsatisfactory coarse grainonly 0.15 to 0.25percent being used in the chrome- size will be developed in the hardened steel.molybdenum steels; the chromium content varies

2-16. Success ful hardening of s teel wil l largelyfrom 0.80 to 1.10 percent. Molybden um is verydepend upon t he following factors af ter steel ha ssimiliar to tungsten in its effect on steel. In somebeen selected w hich has ha rden a bility desires:insta nces it is used to replace tungsten in cutt ing

tools, however; the heat treat chara cterist ic varies. a . Cont rol over the r a te of hea t ing , speci f i -The addition of up to 1%molybdenum gives steel a cally to prevent cracking of thick and irregularhigher tensile strength a nd elastic limit with only sections.a slight reduct ion in ductility. They are especiallyadaptable for welding and for this reason are used b . Thorough and un iform hea t ing through sec-principally for welded structural parts and assem- tions to the correct ha rdening temperatures.blies. P a rts fabr icated from 4130, a re used exten-

c. Cont rol of furnace a tmosphere, in the casesively in t he construction of a ircraf t , m issiles, andof certa in steel parts , t o prevent scaling an dmiscellaneous G SE eq uipment. The 4130 a lloy isdecarburization.used for parts such as engine mounts (recipro-

cating), nuts, bolts, gear structures, support brack- d . Cor rect hea t capac it y , viscos it y , and tem-ets for a ccessories, etc. perat ure of quenching medium t o harden a de-

quately and to avoid cracks.2-13. P R INC IP L ES OF HEAT TREATMENT OFSTEELS. e . In addi t ion to the preceding f actor s , the

thickness of the section controls the depth of hard-2-14. H AR DE NI NG . At or din a r y t em per a t ur es , ness for a given steel composition. Very t hick sec-the carbon content of steel exists in the form of t ions may not ha rden thr ough because of the low part icles of iron carbide scatt ered throughout the rate of cooling at the center.iron ma trix; the na ture of these car bide par ticles,i. e., t h eir nu mb er , s iz e, a n d d is tr ib ut ion , d et er - 2-17. Wh en hea t in g s teel, t h e t em per a t ur em in es t he h a r d nes s a n d st r en g t h of th e s t eel . At s hou ld be d et er m in ed by t h e u se of a ccu r a t eeleva t ed t em per a t u res , t h e ca r b on is d is solved in ins t ru m en t s. At t imes , h ow e ver , su ch in st r u men t st h e i ron m a t r ix a n d t he ca r b id e-pa r t i cl es a ppea r a r e n ot a va i la b le, a n d in s uch ca s es , t h e t em per a -only a f ter th e steel has cooled through its ‘‘cr it ica l t ur e of th e s teel ma y be ju dg ed a ppr oxim a t el y b ytemperature ’’ (see para gra ph 2-15). I f t h e r a t e of it s col or . Th e a ccu ra cy w i th w h ich t em per a t ur es

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m a y b e ju dg ed b y color d epen ds on t h e exper ien ce 2-20. Q U E NC H I NG M E D IU M .of the w orkma n, the light in w hich the work is

2-21. Oil is much s lower in ac t ion than w a ter ,being done, the character of the scale on the steel,an d th e tendency of heated steel to warp or crackthe amount of radiated light within the furnace,wh en quenched ma y be greatly reduced by its use.an d th e emissivity or tendency of steel to ra diat eUnfortunately, parts made from high carbon steelor emit light.will not develop maximum ha rdness when

2-18. A n um ber of liq uid s m a y be used for q uen ch ed in oil u nless t hey are q uit e t hin in cr ossquench ing s tee l. Both the medium and the form of sect ion . In a i r cr a f t , however , it i s genera l ly usedthe ba th depend la rgely on the na ture of the work and is recommended in a l l ca ses where i t w i ll pro-t o be cooled . I t is im por ta n t t ha t a su ff icien t d uce t he d es ir ed d eg ree of h a rd ness.qua ntity of the medium be provided to allow themeta l to be quenched without causing a n a pprecia- NOTEble chan ge in the temperat ure of the ba th . This is Alloy steels should n ever be qu enchedparticularly important where many art icles are to in water .be quenched in su ccession.

2-22. In cert a in cases wa t er i s used in thequenching of steel for the har dening process. TheNOTEwater bath should be approximately 18oC (65oF),Aerators may be used in the Quenchas extremely cold water is apt to warp or crack theTanks to help dissipate the vaporsteel and water above this temperature will notbarrier.produce the required hardness.

2-19. QU E NC H ING P ROC E DU RE . Th e t en -2-23. A 10%, salt brine (sodium chloride) solutiondency of steel to wa rp an d crack during theis used when higher cooling rates are desired. Aquenching process is difficult to overcome, and is10%salt brine solution is made by dissolving 0.89due to the fact th at certa in part s of the art icle coolpound of salt per ga llon of wa ter.more rapidly tha n others. Whenever t he ra te of

cooling is not uniform, internal stresses are set up 2-24. For many a r t icles such as mi l ling cu t te rson the metal which may result in warpage or an d similar t ools , a ba th of wa ter covered by acracking, depending on the severity of the stresses. f ilm of oil is occa sionally used. When th e steel isIrregularly shaped parts are particularly suscepti- plunged th rough this oil f ilm a thin coating w illble to these conditions although parts of uniform adhere to it, retarding the cooling effect of thesection size are oft en af fected in a similar ma nner. wa ter slightly, thus reducing the tendency to crackOpera tions such a s forging a nd ma chining ma y set due to contraction.up internal str esses in steel par ts a nd it is t here-

2-25. STRAIGH TENING OF P ARTS WARPE Dfore a dvisable to normalize a rt icles before a tt empt-I N QU E N C H I NG . Wa r ped pa r t s m us t b eing th e hard ening process. The following recom-straightened by first heating to below the temper-mendations will greatly reduce the warpinging temperature of the art icle, and th en applyingtendency and should be carefully observed:pressure. This pressure should be cont inued unt il

a . An a r t icle should never be thrown in to th e piece is cooled. It is desira ble to retemper thequenching media /ba th . B y permit ting it to lie on par t a f t er s t ra ightening a t the s t ra ightening tem-the bottom of the bat h it is apt to cool fast er on pera ture. No at tempt should be ma de tothe top side than on t he bott om side, thus causing straighten hardened steel without heating, regard-it to wa rp or crack. less of the number of times it has been previously

heat ed, as st eel in its ha rdened condition cannotb . The a r t icle should be sl igh t ly ag i t a ted inbe bent or sprung cold with any degree of safety.the ba th to destroy th e coating of vapor which

might prevent it from cooling rapidly. This allows 2-26. TE MP E R IN G (D R AWI NG ). S t eel t h a tthe ba th t o remove the heat of the a rt icle ra pidly

has been hardened by rapid cooling from a pointby conduction a nd convection. slightly above its crit ical r an ge is of ten ha rdertha n necessary an d generally too brit t le for mostc. An a r t icle should be quenched in such apurposes. In ad dition, it is under severe intern a lmanner that all parts will be cooled uniformly andstr ess. In order to relieve th e str esses a nd reducewit h the lea st possible distort ion. For exam ple, athe brit t leness or restore ductility t he meta l isgear w heel or shaf t should be quenched in a ver-a lways ‘‘tempered ’’. Tempering consists in rehea t-ticle position.ing the st eel to a temperature below the crit ical

d. I rregula rly sh aped sect ion s sh ould be r an ge (usua lly in th e n eigh borh ood of 600 -im mer sed in such a ma nn er t ha t th e pa rt s of t he 1200oF). This reheat ing causes a coa lescence a ndg rea t e st s ect ion t h ick nes s en t er s t h e b a t h f ir st . en la r g em en t of th e f in e ca r b id e pa r t i cl es pr od uced

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by dras t ic quench ing , and thus t ends to sof ten the bending , and weld ing . Normal iz ing may be accom-s tee l. The des ired st reng th wan ted w i l l determine plished in furnaces used for annea l ing . The a r t i -the tempering tempera ture . This i s accomplished cles a re put in the furnace and hea ted to a poin tin th e s a m e t y pes of fu r na ces a s a r e u sed for h a r d- a p pr oxima t e ly 150o to 225oF a bove the crit icalen in g a n d a n n ea l in g. L es s r ef i ned m et h od s a r e t em per a t ur e of t h e s teel. Af t er th e pa r t s h a vesom et im es used for tem per in g sm a ll t ools. been held at t his tem per at ur e for a suf f icien t t im e

for t he part s to be heated uniformly throughout,2-27. As in the case of hardening, tempering they must be removed from the furnace and cooledtemperatures ma y be a pproximately determined in st ill air . P rolonged soaking of the metal a t highby color. These colors a ppear only on th e surfa ce temperatures must be avoided, as t his practice wilan d a re due to a th in f ilm of oxide which forms on cause the gra in structure to enlar ge. The lengththe metal after the temperature reaches 232oC of t ime required for the soaking t empera ture w ill(450oF). In order to see the tempering colors, the depend upon th e ma ss of metal being tr eat ed. Thesurface must be brightened. A buff stick consisting optimum soaking time is roughly one-quarter hourof a piece of wood with emery cloth attached is per inch of diameter or thickness.ordina rily used for this purpose. When tempering

2-30. C AS E H AR DE N IN G . I n ma n y in st a ncesby th e color meth od, a n open f lam e of heat ed ironit is desirable to produce a ha rd, w ear-resista ntplate is ordinarily used as the heating medium.surface or ‘‘case’’ over a strong, tough core. Trea t-Although the color method is convenient, it shouldment of this kind is known as ‘‘case hardening ’’.not be used unless adequate facilities for determin-This trea tment ma y be a ccomplished in severa ling tempera tur e a re not obta ina ble. Tempering

ways, the principal ways being carburizing, cya-temperatures can also be determined by th e use ofniding, and nitriding.crayons of known m elting point . Such crayons are

commercially a vaila ble for a w ide range of temper- 2-31. Flame Ha rdening/Softening. Surface hard-atures under the trade name of ‘‘Tempilstiks’’. The ening/soft ening by a pplying intense hea t (such asabove method may be used where exact properties tha t produced by a n Oxy-Acetylene f lam e) can beaf ter tempering is not t oo importa nt such a s for accomplished on almost any of the medium carbonblacksmit h work. The most desireable method for or al loys st eel, i.e. 1040, 1045, 1137, 1140 etc.genera l a erona utical use, is to determine tempera- The part s a re surface hardened, by a pplying atures by ha rdness checks, and subsequent a djust- reducing f lame (An Oxidizing f lame should neverments ma de as necessary t o obta in th e properties be used) at such a rate, that the surface is rapidlyrequired. For recommend ed tempering tempera- heated to the proper quenching temperature fortur es see heat t rea t da ta for mat erial/composition the steel being trea ted. Following the applicat ioninvolved. of the heat , the part is quenched by a spraying of

wa ter/oil ra pidly. The fa st quench ha rdens the2-28. Steel is usually subjected to the annealing steel to the depth that the hardening temperatureprocess for the following purposes:

ha s penetra ted below t he surface. The actua l ha rd-ness resulting will depend on the rate of coolinga . To increase it s duct i li t y by reducing ha rd-from the quenching tempera ture. In ha rdening byness and brit t leness.this m ethod th e shape a nd size/ma ss of th e partmust be considered. Most operat ions will requireb . To ref ine the cryst a l l ine s t ructure andspecial ad apted spra y nozzles to a pply t he quench-remove stresses. St eel wh ich ha s been cold-ing media, which is usually wat er. Normally,worked is usually a nnealed so as t o increase itsf lame ha rdening will produce surface hardnessductility . H owever, a large a mount of cold-dra wnhigher tha n can be obtained by routine furnacewire is used in its cold-worked state when veryheating a nd quenching, because surface can behigh yield point a nd t ensile strength a re desiredcooled at a faster ra te. If a combinat ion of highan d relat ively low ductility is permissible, as instrength core and surface is required some of thespring wire, piano wire, and wires for rope and

medium carbon alloy steels can be heat t reatedcable. Hea ting to low temperat ures, as in solder- an d subsequently surface ha rdened by the f lameing, will destroy these properties. How ever, ra pidmethod.heat ing wil l narrow the a f fected a rea .

NOTEc. To sof ten the ma ter ia l so tha t mach in ing ,forming, etc., can be performed. This method is not adapted for sur-

face hardening of part s for use in crit-2-29. NORMALIZING. Al though involving a

ical applications.slightly different heat treatment, normalizing mayb e cla s sed a s a for m of a n n ea l in g. Th is pr oces s 2-32. S u rf a ce s of t en in g is a ccom plis hed by hea t -a l so r em oves st r es ses d ue to m a ch in in g , f or ging , ing t h e s ur fa ce t o ju st b elow t h e t em per a t u re

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r eq ui red for h a rd en in g a nd a llow i ng t he ma t er ia l 2-38. S olid , l iq uid , a n d ga s ca r bu riz in g met h od sare employed.to cool (in a ir) na tur a lly. This meth od is some-

times used to soften material that has been hard-a . The s imples t method of carbur iz ing con-ened by frame cutt ing. Oft en it is necessary to

sists of soaking the parts at an elevated tempera-apply the heat in short intervals t o preventture w hile in conta ct w ith solid car bona ceousexceeding the h ar dening temperature.ma terial such as w ood charcoal, bone charcoal a nd

charred leather.2-33. Induct ion. Ha rdening/Heat ing. The induc-tion method of heat ing can be used to surface

b . L iquid ca rbur iz ing cons is t s of immers ingharden steels , in a manner similar to that used forthe par ts in a l iquid sa l t ba t h , heated to thef lame ha rdening. The exception is tha t the heatproper temperat ure. The carbon penetra tes thefor ha rdening is produced by placing the pa rt in asteel as in the solid method producing the desiredmagnetic field (electrical) specifically designed forcase.the purpose. P ar ts ha rdened (surface) by this

method will be limited to capability and size of c. Ga s ca rbur iz ing cons is t s of hea t ing theloop/coil used t o produce the m a gnet ic f ield. parts in a retort and subjecting them to a carbona-

ceous gas such as carbon monoxide or the common2-34. In some ins tances the induct ion method

fuel ga ses. This process is par ticula rly ada pta blecan be used to deep harden; the extent will depend

to certa in engine part s .on exposure/dw ell time, int ensity of the m a gneticf ield, an d the size of the part to be treated. 2-39. When pack ca rbur iz ing , the pa r t s a re

packed with the carburizing material in a vented2-35. CARB U RI ZI N G . At eleva t ed t em per a -steel container to prevent the solid carburizing

tures iron can react w ith ga seous carbon com-compound from burning a nd t o retain t he carbon

pounds to form iron carbide. B y heatin g steel,monoxide and dioxide ga ses. Nichrome boxes,

while in contact w ith a carbon-aceous substa nce,capped pipes of mild steel, or welded mild steel

carbonic gases given off by th is ma terial w ill pene-boxes ma y be us ed. Nichrome boxes a re most eco-

trate the steel to an amount proportional to thenomical for production because they withstand oxi-

time and t empera ture. For example, if mild orda tion. Ca pped pipes of mild steel or welded mild

soft steel is heated to 732oC (1,350oF) in an steel boxes a re useful only as subst itut es. Theatmosphere of carbonic gases, it will absorb carbon container should be so placed as to allow the heatfrom the gas until a carbon content of approxi- to circulat e entirely ar ound it. The furna ce mustmately 0.80 percent has been attained at the sur- be brought t o the car burizing tempera ture a sface, this being the saturation point of the steel for quickly a s possible and held at this heat from 1 tothe particular temperat ure. B y increasing the 16 hours, depending upon the depth of caseheat to 899

o

C/(1,650o

F) the same steel will absorb desired an d the size of the work. Af ter carbu-carbon from t he gas until a carbon content of rizing, the container should be removed andapproximat ely 1.1 percent ha s been at ta ined, allowed to cool in air or the parts removed fromwhich is th e sat urat ion point for t he increased the carburizing compound and quenched in oil ortemperature. w a ter. The air cooling, alth ough slow, reduces

wa rpage and is a dvisable in many cases .2-36. The carburiz ing process may be applied toboth plain carbon and alloy steels provided they 2-40. Carbur ized s tee l pa r t s a re r a re ly usedar e with in the low carbon range. Specifically, the without subsequent heat treatment, which consistscarburizing steels a re those containing n ot more of several steps to obta in optimum ha rdness in theth an 0.20 percent carbon. The lower t he ca rbon case, and optimum strength and ductility in thecontent in the st eel, the more readily it w ill core. G ra in size of the core and case is ref ined.absorb, carbon during the carburizing process.

a . Ref in ing the core i s accomplished by

2-37. The amount of carbon absorbed and the reheating t he parts t o a point just a bove the crit i-thickness of the case obtained increases with t ime; cal temperat ure of the steel. After soaking for ahowever, the carburization progresses more slowly suff icient t ime to insure uniform heating, th eas the carbon content increases during the process. part s a re quenched in oil.The length of time required to produce the desireddegree of carburizat ion ma terial used a nd th e tem- b. The hardening tempera ture for the h ighpera ture to which the meta l is subjected. It is carbon case is well below tha t of th e core. It is,apparent that , in carburizing, carbon travels therefore, necessary to heat the parts again to theslowly from the outside toward the inside center, crit ical t empera ture of the case an d quench themand therefore, the proportion of carbon absorbed in oil to produce the required hardness. A soakingmust decrease from the outside to the inside. period of 10 minutes is generally sufficient.

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c. A f in a l s t res s r el iev in g oper a t i on is n eces - f l a king of t h e n it r id ed ca s e. Wh en no d is t or t ion iss a ry to minimize the ha rden ing st resses produced permiss ib le in the n i t r ided par t , i t is necessa ry tob y t h e pr ev iou s t r ea t m en t . Th e s t res s r el iev in g n or m a li ze t h e s t eel pr ior t o n it r id in g to r em ove a l ltemperature is generally around 350oF . Th is is s tr a in s r esu lt in g fr om t he for gin g, q uen ch in g, ora ccom pli sh ed b y h ea t in g, s oa k in g u nt il u ni for mly m a ch in in g.hea ted, an d cooling in still air. When extreme

2-43. H E AT TRE ATI N G E Q U I PM E N T. E q u ip-ha rdness is desired, th e temperature should bement necessary for heat trea ting consists of a suit-carefully held to the lower limit of the range.able means for bringing the meta l to the required

2-41. C YAN ID I NG . S t eel pa r t s m a y be s ur fa ce- temperature m easuring a nd controlling device an dhardened by heating while in contact with a quenching medium. Hea t ma y, in some insta nces,cyanid salt , followed by quenching. Only a thin be supplied by means of a forge or welding torch;case is obta ined by this method an d it is , there- however, for the treatment required in aircraftfore, seldom used in connection with aircraft con- work, a furna ce is necessary. Various jigs and f ix-struction or repair . Cya niding is, however, a rapid tures are sometimes needed for controlling quench-an d economical method of case ha rdening, an d ing and preventing warping.ma y be used in some insta nces for relat ively unim-porta nt par ts . The work to be hardened is 2-44. F U RN AC E S . H ea t t rea t in g fu rn a ces a reimmersed in a bat h of molten sodium or pota ssium of many designs and no one size or type perfectlycyan ide from 30 to 60 minut es. The cya nide bat h fills every heat t reating requirement. The sizeshould be maintained at a temperature to 760oC t o and q uant i ty of meta l to be t rea t ed and the var i-

899oC (1,400oF to 1,650oF). Immedia tely af ter ous trea tments r equired determine the size andremoval from the bath, the parts are quenched in type of furnace most suitable for each individualwa ter. The case obta ined in this ma nner is due case. The furnace should be of a suitable type andprincipally to the formation of carbides and design for the purpose intended and should benitr ides on th e surfa ce of the steel. The use of a capable of ma inta ining with in the w orking zone aclosed pot and ventilating hood are required for temperature va rying not more tha n + or - 14oCcyaniding, a s cyanide vapors are extremely (25oF) for the desired value.poisonous.

2-45. HE AT TREATING FURNACES/BATHS .2-42. N ITR ID I NG . Th is m et h od of ca s e h a r d -ening is advantageous due to the fact that a 2-46. The accepta ble heat ing media for heatharder case is obtained than by carburizing. Many treating of steels are air, combusted gases, protec-engine parts such as cylinder barrels and gears tive at mosphere, inert at mosphere or va cuum fur-may be treated in this way. Nitriding is generally naces, molten-fused salt baths, and molten-lead

applied to certain special steel alloys, one of the ba ths. The hea t trea ting furna ces/ba th s a re ofessentia l const ituent s of w hich is a luminum . The many designs and no one size or type will perfectlyprocess involves the exposing of the parts to f ill every heat tr eating requirement. Furna cesam monia ga s or other nit rogenous mat erials for 20 and baths shall be of suitable design, type andto 100 hours at 950oF. The cont a iner in w hich th e const ruction for purpose intend ed. P rotective a ndwork and ammonia gas are brought in contact inert a tmospheres shall be ut ilized a nd circulat edmust be airt ight and capable of maintaining good as necessary to protect all surfaces of parts com-circulation a nd even tempera tur e th roughout. The prising t he furna ce load.depth of case obtained by nitriding is about 0.015inch i f h ea t e d f or 50 h ou r s. Th e n it r id in g pr oces s 2-47. Th e d es ig n a n d con st r uct ion of t h e h ea t in gdoes not a f fect the phys ica l s t a te of the core i f the equipment sha l l be such tha t the furnace/ba th i spreceding tempering t empera ture w as 950oF or ca pa ble of ma int a inin g w it hin the w orking zone, a tover . Wh en a pa r t is to b e on ly pa r t ia l ly t rea t e d, a n y point , a t em per a t u re va r ying not m or e t h a ntinning of an y surfa ce will prevent it from being ±25oF (±14oC) from the required heat treating tem-

n it r id ed . N it r id ed s ur fa ces ca n b e r eh ea t ed t o per a t ur e, w it h a n y ch a rg e. Af t er t h e ch a r ge h a s950oF wi th ou t los ing any of the ir ha rdness , how- been brought up to t rea t ing/soaking tempera tureever , i f h ea t e d a b ove t h a t t em per a t u re, t he h a r d - a l l a r ea s of t he w or king zon e s ha l l b e w i t hin t h en es s is r a pid ly los t a n d ca n n ot be r eg a in ed by per mis si ble t em per a t ur e r a n ge s pecif i ed for t her et r ea t m en t . P r ior t o a n y n it r id in g tr ea t m en t , a l l s t eel/a l loy being h ea t t r ea t e d (S ee Ta ble 2-3, MIL-d eca r b ur iz ed m et a l m us t be rem oved t o pr even t H-6875 or en g in eer in g da t a f or m a t er ia l in volved ).

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NOTE furnaces, a minimum of 9 test thermocouples or 1per 25 cubic feet, whichever is greater, shall beSpecification SAE-AMS-H-6875, Heatused. Bath furnaces shall be tested by use of aTreatment of Steel, will be the controlminimum of 5 test locations or 1 per each 15 cubicdocument for heat treating steelfeet. The locations may be surveys, using suitablematerial to be used on aerospaceprotected multiple or single brake test thermocou-equipment. Where new alloys areples. For distribution of test thermocouples, see

involved, it will be necessary to Figure 2-1. Temperature measuring and recording review the involved specification orinstruments used for controlling the furnace shallmanufacturer’s engineering or designnot be used to read the temperature of the testdata for the appropriate heat informa-temperature sensing elements.tion (temperature, control, atmos-

phere, times, etc). In case of conf lict 2-52. For all surveys, the furnace or bath tem-the Military/Federal Specif ication will perature shall be allowed to stabilize at the poten-be governing factor or the conf lict will tial test temperature. The initial survey shall bebe negotiated with the responsible made at the highest and lowest temperatures of technical/engineering activities for the furnace specified operating range. Periodicresolution. surveys may be made at a convenient temperature

within the operating range. The temperature of 2-48. HEAT CONTROL, FURNACE TEMPERA-all test locations/thermocouples shall be recordedTURES SURVEY AND TEMPERATURE MEA-at 5 minute intervals, starting immediately afterSURING EQUIPMENT.

insertion of the test thermocouples in the furnace2-49. Furnaces/baths shall be equipped with or bath. Reading shall be continued for 1/2-hoursuitable automatic temperature control devices, or more after furnace control thermocouple readsproperly calibrated and arranged, preferably of the within 25oF of original setting. After all the testpotentiometer type to assure adequate control of thermocouples have reached the minimum of thetemperature in all heat-treating zones. The heat treating range, their maximum variationresulting temperature readings shall be within shall not exceed ±25oF (14oC) and shall be within±1.0 percent of the temperature indications of the the specified heat treating temperature range incalibrating equipment. Thermocouples shall be accordance with Specification SAE-AMS-H-6875 orproperly located in the working zones and ade- Table 2-3. If the test indicates that conditions arequately protected from contamination by furnace not satisfactory, the required changes shall beatmospheres by means of suitable protecting made in the furnace and arrangements of thetubes. charge. The furnace control couples shall be cor-

rected for any deviation from the standard electro-2-50. A survey shall be made before placing anymative force (EMF) temperature chart as deter-new furnace in operation, after any change ismined in calibration of the couples.made that may affect operational characteristics,

and semi-annually thereafter to assure conform- 2-53. FURNACE CONTROL INSTRUMENTSance with temperature and control requirement ACCURACY.previously cited. Where furnaces are used only for

2-54. The accuracy of temperature measuring,annealing or stress relieving, an annual surveyrecording and controlling instruments shall bewill be acceptable. The survey may be waived atchecked at regular intervals, not exceeding 3the discretion of the authorized inspector or repre-months or upon request of personnel in charge orsentative provided that the results from previousauthorized (Government) inspector or representa-tests, with the same furnace or bath and sametives. The accuracy of the instrument shall betype of load, show that the temperature and con-made by comparison tests with a standardized pre-trol uniformity is within specified limits. As acision potentiometer type instrument of knownpart of the inspection thermocouples should be(tested) accuracy used with a calibrated thermo-

closely inspected for condition and those severely couple. The test thermocouple shall be locateddeteriorated and of doubtful condition should beapproximately 3 inches from the installed furnacereplaced.thermocouple(s). The temperature for check shall

2-51. The initial and succeeding (semi-annual be at working temperature with a production load.and annual) surveys shall be performed with a If instruments are replaced or not used for 3standard production type atmosphere, controlled if months they shall be checked before use.required. A minimum of 9 test thermocouples or 1per 15 cubic feet, whichever is greater, shall beused for air furnaces except circulating air fur-naces used for tempering only. In the tempering

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Fi gure 2-1. N umber and D istri buti on of Thermocouples

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2-55. S ALT B ATH C ONTROL . Tabl e 2-1. Soaking Peri ods for H ardening N ormal iz ing and Ann eali ng (Plain Carbon Steel)

2-56. The bat h composit ion shall be adjusted asfrequently as necessary to prevent objectionableattachment of the steel or alloy to be treated and TIME OFto permit a t ta inment of the desired mecha nical HEATING TOproperties of the finished product. The bat h will D IAME TE R RE QU IRE D TIME OF

be checked at least once a m onth. OR TE MP E RATU RE H OLD INGTH IC KNE S S (AP P ROX) (AP P ROX)

2-57. Temperature recording should be of theautomatic controlling and recording type, prefera- INCH E S H OU RS H OU RSbly th e potent iometer type. Thermocouples shouldbe placed in a suitable protecting tube, unless the 1 a nd less 3/4 1/2furnace at mosphere is such th at undue deteriora- Over 1 1 1/4 1/2tion of the thermocouples will not result. through 2

Over 2 1 3/4 3/42-58. QU E NC H ING TANKS AND LIQUIDS.

through 3Suita ble tanks m ust be provided for quenching

Over 3 2 1/4 1ba ths . The size of ta nks should be suff iciently

through 4large to allow th e liquids to remain a pproximat ely

Over 4 2 3/4 1at room temperature. Circulating pumps and cool-

through 5ers may be used for maint aining a pproximately

Over 5 3 1/2 1 1/2constant temperatures where a large amount of through 8quenching is done. The locat ion of these ta nks isvery important due to the fact that insufficiently

2-63. H AR D E NI NG . Tem per a t ur es r eq uir ed forra pid tran sfer from th e furnace to the quenchinghardening steel are governed by the chemical com-medium may destroy the effects of the heat treat-position of the steel, previous treatment, handlingment in many instances.equipment, size and shape of piece to be treated.

2-59. The quenching l iquids commonly used are Generally, parts of heavy cross section should bea s follows: Wa ter at 18oC (65oF), Commercial ha rdened from t he high side of the given tempera-Quenching Oil, and Fish Oil. ture range.

2-60. H EAT TREATING P ROCEDU RES . 2-64. TE M P E R IN G (D R AWI NG . ) Tem per in gconsists of heating the ha rdened steel to the a ppli-cable temperat ure holding at this temperat ure forNOTEapproximately 1 hour per inch of the thickness of

Additional Hea t Treat ment informa- the largest section, and cooling in air or quenchingtion is discussed in Section IX.

in oil at approximat ely 27o to 66oC (80o to 150oF).2-61. I NI TI AL FU R N AC E TE M P E R ATU R E S . Th e t em per a t ur e t o b e u sed for tem per in g of s teelI n nor m a li zing , a n n ea l in g a n d ha r d en in g w h er e d ep en d s u pon t he ex a ct ch em ica l com pos it i on ,pa r t s a r e n ot pr eh ea t e d, t h e t em per a t u re in t h a t h a r d nes s, a n d gr a in s t ru ct u re ob t a in ed by h a r d en -z on e of t h e fu rn a ce w h er e w or ks is in t rod uced in g a n d t h e m et h od of t em per in g. Th e t em per in gshould be at least 149oC (300oF ) b el ow t h e w or k- t em per a t ur es g iv en a re on ly a ppr oxim a t e, a n d t h eing tempera ture a t the t ime of inser t ion of pa r t s of exac t t empera ture should be determined by ha rd-s im ple d es ig n. F or p a r ts of com pl ica t e d d es ig n n es s or t en sion tes t f or ind iv id u a l pieces . Th einvolving a br u pt ch a n g e of sect ion or sh a r p cor - f in a l t em per in g t em per a t u res sh ou ld n ot b e m or eners, the temperatur e should be at least 260oC t ha n 111oC (200oF) below the tempering, tempera-(500oF) below the working tempera ture. The fur- ture g iven . I f the cen ter of the sect ion is morenace must be brought to the proper t empera ture tha t 1/2-inch from the surface , the t ens ile s t reng th

gra dua lly. a t t he center w ill in genera l be reduced; t herefore,a lower tempering temperature should be used for2-62. S OAK I NG P E R I OD S . Th e per iod of s oa k -

sections thicker than 1 inch in order to obtain theing is governed by both the size of the section and

required tensile strength.th e nat ure of th e steel. Ta ble 2-1 indicat es in ag en er a l w a y t h e ef fect of si ze on t he t im e for soa k - 2-65. AN NE AL I NG . An nea l in g con sis ts ofing . Th is t a ble i s int en d ed t o b e u sed a s a g uide h ea t in g t o t h e a p pl ica b le t em per a t u re, h olding a ton ly and should not be cons t rued as being a man- th is t empera ture for approx ima te ly the per iod ofd a t or y req u ir em en t . I t a p pl ies on ly t o pl a in ca r - t ime g iven , a n d cool in g in t h e f ur n a ce t o a t e mper -bon a nd low a lloy steels. a t ure not higher t ha n 482oC (900oF). The st eel

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may then be removed from the furnace and cooled betw een the tens ile s t reng th and hardness i s indi-in st ill air . cated in Ta ble 8-3. This ta ble is to be used a s a

guide. It a pplied only to the plain carbon and low 2-66. N OR MAL I ZI NG . N or m a liz in g con sis ts of

alloy steels not to corrosion-resistant, magnet,heat ing the steel to the a pplicable temperatur e,

va lve, or tool steels. When a na rrow ra nge ofholding at this temperature for period of time,

ha rdness is required, the tests to determine theremoving from furnace and cooling in still air.

relat ionship between hardness and strength2-67. C AR B U RI ZI NG . C a rbu rizin g con sis ts of sh ou ld be m a de on t he a ct ua l pa r t. H a r dn ess v a l-heat ing the steel packed in a car burizing medium, ues should be within a ra nge of t wo pointsin a closed container, to the applicable tempera- Rockwell or 20 points B rin ell or Vickers. The ten-ture a nd holding at this temperat ure for th e neces- sile strength-ha rdness relat ionship is quit e uni-sary period of time to obtain the desired depth of form for parts which are sufficiently large andcase. 1020 steel will require 1 to 3 hours a t a rigid to permit obtaining a full depression on acarburizing temperature of 899oC (1650oF) for f lat surface without def lection of the piece. Foreach 1/64 inch of ca se depth , required. P a rts ma y cylindrical part s of less tha n 1 inch in diam eter,be cooled in the box or furnace to a temperature of the Rockwell reading w ill be lower tha n indicatedapproximately 482oC (900oF) th en air cool. This in the table for the corresponding tensile strength.treatment leaves the alloy in a relat ively soft con- Any process which affects the surface, such asdit ion a nd it is then necessary t o condition by buff ing a nd plat ing, or t he presence of decar bu-heat ing an d quenching, first for core refinement, rized or porous a reas a nd ha rd spots, will af fect

followed by h eating an d quenching for case ha rd- the corresponding relation betw een ha rdness an dness. Alloy ma y be quenched directly from the tensile strength . Therefore, these surfa ces mustcarburizing furnace, thus producing a ha rd case be adequa tely removed by grinding before mea-a nd a core ha rdn ess of Rockwell B67. This trea t- surements are made.ment produces a coarse grain in some types ofsteel an d ma y cause excessive distortion. Usua lly 2-72. In making ha rdness measurements onth ere is less distortion in fine gra in steels. The tubular sections, correction factors must be deter-core treat ment outlined above refines the gra in as mined a nd a pplied to the observed readings inwell as hardens. order to compensa te for the roundn ess and def lec-

tion of the tubing under the pressure of the pene-2-68. H AR DNE SS TES TING .tra tor. This may be impra ctical because every

2-69. G E N ER AL . H a r dn ess t est in g is a n tube size end wa ll thickness would have a differ-important factor in the determination of the ent factor. As an alternate, the following procedureresults of the heat treatment as well as the condi- may be used: Short lengths may be cut from the

tion of the metal before heat treatment and must, tube. A mandrel long enough to extend out bothth erefore, be ca refully considered in connection ends of the tube a nd slightly sma ller in dia meterwith this work. The methods of hardn ess testing than the inner diameter of the tube is then passedin general use are: the Brinell, Rockwell, Vickers, through t he section an d t he ends supported in ‘‘V’’a nd Sh ore Scleroscope. Ea ch of these meth ods is supports on the hardness tester. Ha rdness read-discussed in section VIII. ings may then be taken on the tubing.

2-70. TE N S IL E S TR E NG TH . Tem per in g t em -2-73. SP ECIFICATION CROSS RE FERENCE.

pera tures listed w ith t he individual steels in TableTable 2-2 is a cross reference index listing the

2-3 are offered as a guide for obtaining desiredsteel and alloy types and the corresponding Fed-

tensile and yield strength of the entire cross sec-eral, Military, and aeronautical material specifica-

tion. When the physical propert ies a re specifiedtions for the different configurat ions. Where t wo

in terms of tensile strength, but t ension tests a reor more specifications cover the same material,

impractical, har dness tests ma y be employed usingstock ma terial m eeting t he requirements of a mili-

the equivalent ha rdness values specif ied in Tableta ry specificat ion sha ll be used for a ll aeronautical8-3.stru ctura l items. Some of th e specif ications listedin Ta ble 2-2 a re for reference only, and are not2-71. HARDNESS-TENSILE STRENGTH RELA-approved for Air Force use.TIONSHIP. The approx ima te rela t ionsh ip

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Tabl e 2-2. Specifi cati on Cross Reference

COMP /ALLO YD E S IG N FORM/COMMOD ITY AMS FE D E RAL MILITARY

1005 Rod, w elding steel a nd 5030 MIL-R-908, C1 1

cast iron, rod a nd w ire,st eel w elding (A/Capplication)

1008 S t eel, sheet a nd st rip, MIL-S -4174f la t , a luminum coat edlow carbon, MIL-S-4174

1010 B a rs, B illet s, B looms, MIL-S -16974Slabs

B a rs (G enera l P urpose) QQ-S -633 MIL-S -11310

Wire QQ-W-461

S heet a nd S t r ip 5047 QQ-S -698

S heet a nd S t r ip 5040



Tubing, S ea mless

Documents

TM-43-0106 - TECHNICAL MANUAL ENGINEERING SERIES FOR AIRCRAFT REPAIR AEROSPACE METALS - GENERAL DATA AND USAGE FACTORS