Preface..................... xi About the Author......... xiii Acknowledgments... xiv Unit 1 1 Bases for Interpreting Drawings........ I Visible Lines............. 3 Lettering on Drawings... 3 Sketching... 3 Third-Angle Projection........... 3 ISO Projection Symbol............... 6 Title Block........ 7 A-I....Sketching Missing Views... 9 A-2.... Sketching Three Views... 10 A-3... Sketching Pictorial Views... 11 Unit2 12 Working Drawings................ 12 Dimensioning......................12 Linear Units of Measurement........... 14 SI (Metric) Units of Measurements... 15 Choice of Dimensions............ 16 Basic Rules for Dimensioning.......... 16 Information Shown on Drawings.17 Reference..........................l 7 A-4M... Corner Block... 18 A-5....Step Bracket...... 19 A-6..... Counter Clamp Bar...... 20 A-7... Dimensioning...... 21 Unit3 22 The Drafting Office.......... 22 Drawing Reproduction................ 23 Abbreviations Used on Drawings.... 25 Hidden Lines........... 25 A-8... Matching Drawings-!... 26 A-9... Matching Drawings-2... 27 A-10... Feed Hopper....... 29 A-ll... Sketching Three Views... 30 Unit4 31 Inclined Surfaces....... 31 Measurement of Angles... 31 A-12... Sketching Three Views...... 34 A-13... Sketching Missing Views.... 35 A-14.... Adapter... 36 A-15M.. Guide Block....... 37 A-16... Base Plate......... 38 UnitS 39 Circular Features............. 39 Center Lines........ 39 Dimensioning of Cylindrical Features.... 40 Dimensioning of Cylindrical Holes.......40 Repetitive Features and Dimensions....40 Drilling, Reaming, and Boring... 40 Identifying Similarly Sized Features... 42 Rounds and Fillets........... 4 2 A-17... Sketching Circular Features.. 43 A-18... Coupling....45 A-19... Sketching Missing Views.... 46 Unit 6 47 Drawing to Scale....4 7 Inch and Foot Scales... 49
~ I' ~%.it%'1f J" vi Interpreting Engineering Drawings '-~t ::~,., SI (Metric Scales)..........49 Machine Slots... 49 Symmetrical Outlines....... 50 Reference Dimensions....50 A-20... Reading Scales... 52 A-21... Measuring with Scales... 53 A-22... Compound Rest Slide... 55 - Unit 7 56 Machining Symbols... 56 Not-to-Scale Dimensions......... 57 Drawing Revisions....... 58 Break Lines... 59 Reference... 59 A-23M.. Offset Bracket... 61 Unit8 62 Sectional Views... 62 Types of Sections... 64 Countersinks, Counterbores, and Spotfaces.. 66 Intersection of Unfinished Surfaces... 67 A-24... Sketching Full Sections... 69 A-25... Slide Bracket... 71 A-26M.. Base Plate... 73 A-27... Sketching Half Sections... 74 Unit 9 75 Chamfers... 75 Undercuts... 75 Tapers... 75 Knurls..... 76 Reference... 76 A-28... Handle....... 78 A-29M.. Indicator Rod... 79 Unit 10 80 Selection of Views... 80 One- and Two-View Drawings... 80 Multiple-Detail Drawings... 80 A-30... Centering Connector Details.83 A-31M.. Link....... 84 Unit 11 85 Surface Texture... 85 Surface Texture Symbol... 88 Surface Texture Ratings....... 88 Control Requirements....... 89 Reference.......................... 90 A-32... Sketch Missing Views... 93 A-33... Hanger Details... 95 Unit 12 96 Tolerances and Allowances... 96 Definitions... 96 Tolerancing Methods...... 97 Reference... 99 A-34... Inch Tolerances and Allowances... 101 A-35M... Millimeter Tolerances and Allowances....... 103 Unit 13 104 Inch Fits... 104 Description of Fits....... 104 Standard Inch Fits....... 106 References... los A-36....Inch Fits Basic Hole System.109 Unit 14 110 Metric Fits....... llo Reference... 112 A-37M... Metric Fits Basic Hole System.ll5 A-38M.. Bracket... ll7 A-39M.. Swivel...... lls Unit 15 119 Threaded Fasteners....... ll9 Threaded Assemblies... ll9 Threaded Holes... 120 Inch Threads... 120 Right- and Left-Handed Threads... 122 Metric Threads....... 122 Reference... 124 A-40....Shaft Intermediate Support.. 125 A-41M.. Drive Support Details... 127
[i; ~ k-!i '1~ "' CONTENTS vii A-42... Housing Details......... 129 Unit 21 164 A-43M.. V-Block Assembly... 130 Unit 16 131 Arrangement of Views............ 164 A-56....Index Pedestal... 167 Revolved and Removed Sections....... 131 A-57.... Mounting Plate...... 168 Reference.................. 131 A-58M.. Contact Arm....... 169 A-44... Terminal Block... 133 A-45... Shaft Supports...... 135 Unit 22 170 Unit 17 136 Piping... 170 Piping Drawings... l 72 Pipe Drawing Symbols......... 174 Keys.............. 136 Reference... l 77 Setscrews.........................137 Flats... 138 A-59.... Engine Starting Air System.. 179 Bosses and Pads................ 138 A-60... Boiler Room... 181 Dimensioning Origin Symbol... 138 Rectangular Coordinate Dimensioning Without Dimension Lines....... 139 Unit 23 182 Rectangular Coordinate Dimensioning in Bearings................. 182 Tabular Form... 139 Plain Bearings... 182 References... 139?remounted Bearings... 184 References................ 184 A-46M.. Terminal Stud... 141 A-47... Rack Details... 143 A-61M.. Adjustable Shaft Support... 185 A-48.... Support Bracket........ 145 A-62.... Corner Bracket........ 187 Unit 18 146 Unit 24 188 Primary Auxiliary Views... 146 Manufacturing Materials... 188 Reference... 146 Steel.............. 188 Plastics................ 190 A-49....Inclined Stop...... 149 Rubber................ 191 A-50... Gear Box........... 150 Unit 19 151 A-63M.. Crossbar......... 193 A-64... Oil Chute.............. 195 A-65M.. Parallel Clamp Details... 196 Secondary Auxiliary Views... 151 A-66M.. Caster Assembly........ 197 Reference............ 152 A-51....Identifying Oblique Surfaces.. 153 Unit 25 198 A-52... Hexagon Bar Support... 155 Castings... 198 A-53... Completing Oblique Surfaces.156 Cast Irons................. 200 Unit 20 157 Casting Design........ 201 Cored Castings..... 203 Machining Lugs............... 203 Development Drawings... 157 Surface Coatings... 204 joints, Seams, and Edges........ 157 References... 204 Sheet Metal Sizes... 157 Straight Line Development... 157 A-67... Offset Bracket... 205 Stampings..... 160 A-68.... Trip Box...... 207 A-69... Auxiliary Pump Base...... 209 A-54... Letter Box............. 162 A-70M.. Slide Valve... 210 A-55M.. Bracket........... 163
"A*'-r& viii Interpreting Engineering Drawings ;.-~:.;, Unit 26 211 Unit 31 247 Chain Dimensioning..... 211 Base Line Dimensioning......... 211 Reference.............. 211 A-71... Interlock Base... 215 A-72M.. Contactor... 216 Unit 27 217 Alignment of Parts and Holes...... 217 Partial Views... 218 Naming of Views for Spark Adjuster..... 219 Drill Sizes........... 219 Reference... 219 A-73... Spark Adjuster..... 221 A-74... Control Bracket........ 223 Unit 28 224 Broken-out and Partial Sections.... 224 Webs in Section... 224 Ribs in Section....... 224 Spokes in Section... 226 Reference... 226 A-75M.. Raise Block... 229 A-76... Coil Frame... 231 Unit 29 232 Pin Fasteners......... 232 Section Through Shafts, Pins, and Keys.. 236 Arrangement of Views of Drawing A-77M.. 236 References... 236 A-77M.. Spider... 239 A-78... Hood........ 241 Unit 30 242 Drawings for Numerical Control... 242 Dimensioning for Numerical Control... 242 Dimensioning for Two-Axis Coordinate System........ 242 A-79... Cover Plate... 245 A-80M.. Terminal Board........ 246 Assembly Drawings... 247 Bill of Material (Items List)... 249 Swivels and Universal Joints... 249 Reference........ 250 A-81... Universal Trolley..... 253 A-82M.. Parallel Clamp Assembly... 255 Unit 32 256 Structural Steel Shapes... 256 Phantom Outlines... 257 Conical Washers... 258 Reference............ 258 A-83... Four-wheel Trolley........ 261 Unit 33 262 Welding Drawings... 262 Welding Symbols... 262 Fillet Welds... 265 References............ 267 A-84... Fillet Welds...... 269 A-85... Shaft Support... 270 Unit 34 271 Groove Welds... 271 Supplementary Symbols... 273 References............. 275 A-86... Base Skid... 277 A-87... Groove Welds... 278 Unit 35 279 Other Basic Welds... 279 References... 285 A-88... Base Assembly...... 287 A-89... Plug, Slot, and Spot Welds.. 288 A-90... Seam and Flange Welds... 289 Unit 36 290 Gears... 290 Spur Gears............... 291 Reference............. 295 A-91....Spur Gear... 297 A-92....Spur Gear Calculations... 298
;:>;j:t''c n =,:/:. CONTENTS ix Unit 37 299 Bevel Gears..... 299 Reference... 299 A-93... Miter Gear... 303 Unit 38 304 Gear Trains........... 304 A-94... Motor Drive Assembly... 307 A-95... Gear Train Calculations... 308 Unit 39 309 Cams....... 309 A-96... Cylindrical Feeder Cam... 313 A-97... Plate Cam... 314 Unit 40 315 Antifriction Bearings............. 315 Retaining Rings............. 317 0-Ring Seals...... 317 Clutches... 317 Belt Drives... 317 References... 321 A-98... Power Drive..... 323 Unit 41 324 Ratchet Wheels... 324 A-99.... Winch... 327 Unit 42 328 Modern Engineering Tolerancing.... 328 Geometric Tolerancing... 330 Feature Control Frame............ 330 Form Tolerances......... 333 Straightness.............. 333 Straightness Controlling Surface Elements.. 333 Reference... 336 A-100... Straightness Tolerance Controlling Surface Elements.339 Unit 43 340 Feature of Size Definitions... 340 Material Condition Symbols........ 342 Examples... 34 2 Maximum Material Condition (MMC)... 343 Regardless of Feature Size (RFS)....... 344 Least Material Condition (LMC)... 344 Straightness of a Feature of Size... 345 Reference............. 349 A-101..Straightness of a Feature of Size.351 Unit 44 352 Form Tolerances... 352 Flatness... 352 Circularity... 353 Cylindricity... 354 Reference............. 355 A-102... Form Tolerances... 357 Unit 45 358 Datums and the Three-Plane Concept... 358 Datums for Geometric Tolerancing... 358 Three-Plane System... 358 Uneven Surfaces....... 359 Datum Feature Symbol........ 361 Reference....... 364 A-103... Datums...... 367 A-104M.Axle..... 369 Unit 46 370 Orientation Tolerancing for Flat Surfaces.370 Orientation Tolerancing for Flat Surfaces.372 Reference.............. 3 73 A-105... Stand... 375 A-106M.Cut-Off Stand... 377 Unit 47 378 Orientation Tolerancing for Features of Size......... 378 Internal Cylindrical Features... 381 External Cylindrical Features...... 384 Reference... 386 A-107... Orientation Tolerancing for Features of Size... 389 Straightness of a Feature of Size... 340
X Interpreting Engineering Drawings " ;1 Unit 48 390 Datum Targets... 390 Datum-Target Symbol........... 390 Reference... 394 A-108... Bearing Housing... 397 Unit 49 398 Tolerancing of Features by Position... 398 Tolerancing Methods... 398 Coordinate Tolerancing... 399 Advantages of Coordinate Tolerancing...402 Disadvantages of Coordinate Tolerancing.402 Positional Tolerancing... 402 Material Condition Basis... 402 Positional Tolerancing for Circular Features.404 Advantages of Positional Tolerancing.... 408 Reference... 409 A-109... Positional Tolerancing... 413 Unit 50 414 Selection of Datum Features for Positional Tolerancing..........414 Long Holes.........414 Circular Datums........... 415 Multiple Hole Datums... 415 Reference............415 A-llO... Datum Selection for Positional Tolerancing.... 418 Unit 51 419 Profile Tolerances....419 Profile of a Line..............419 Profile of a Surface....4 22 Reference... 424 A-1ll... Profile Tolerancing....427 Unit 52 428 Runout Tolerances........ 428 Circular Runout..........428 Total Runout... 430 Establishing Datums.........431 Reference....4 33 A-ll2 Runout Tolerances....435 A-113 Housing.......437 A-ll4M End Plate...........438 APPENDIX 439 Table 1 Chart for Converting Inch Dimensions to Millimeters....439 Table 2 Abbreviations and Symbols Used on Technical Drawings... 440 Table 3 Number and Letter-Size Drills....441 Table 4 Metric Twist Drill Sizes....442 Table 5 Unified and American (Inch) Threads..............443 Table 6 Metric Threads......444 Table 7 Common Cap Screws.....445 Table 8 Hexagon-Head Bolts and Cap Screws....446 Table 9 Setscrews... 447 Table 10 Hexagon-Head Nuts..... 448 Table ll Hex Flange Nuts....449 Table l2 Common Washer Sizes......450 Table 13 Square and Flat Stock Keys....452 Table 14 Woodruff Keys....452 Table 15 American Standard Wrought Steel Pipe....453 Table 16 Sheet-Metal Gages and Thicknesses... 454 Table 17 Running and Sliding Fits an Inch)....455 Table 18 Locational Clearance Fits an Inch)........... 456 Table 19 Locational Transition Fits an Inch)..........457 Table 20 Locational Interference Fits Table 21 Table 22 Table 23 Table 24 Table 25 Table 26 INDEX an Inch)....458 Force and Shrink Fits an Inch)....459 Preferred Hole Basis Metric Fits Description........ 460 Preferred Shaft Basis Metric Fits Description....461 Preferred Hole Basis Metric Fits (Dimensions in Millimeters).....462 Preferred Shaft Basis Metric Fits (Values in Millimeters).......464 Metric Conversion Tables..... 466 467