15 Welding Drafting

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15Welding DraftingSection 15.1Types of Joints, Welds,and SymbolsSection 15.2Producing a WeldingDrawingChapter Objectives Identify types of joints and welds.Explain the weldingprocess.Describe the fusionwelding process.Determine theappropriate joint preparation for a specificweld application.Convert a drawingfor a casting into anappropriate one for awelded part.Team Players Hernandez andMcCollough work as a team bysharing and combining sketchesand ideas they initially comeup with on their own. Haveyou worked on a creativeteam? If so, how did the teammembers work together?524

Drafting CareerProenza Schouler, Fashion DesignersAccording to the fashion press, Proenza Schouler’swomen’s clothes are made for “upscale dressing.”But these upscale clothes often have a sporty, edgy,youthful look with features that remind you of themod look of the sixties, a time when miniskirts andwhite boots were popular. Lazaro Hernandez and JackMcCollough teamed up in design school and createda label using their mother’s maiden names—Proenzaand Schouler. These award-winning designers haverisen quickly to the top of the fashion design world.One remarkable aspect of Proenza Schouler’s success is that their popular clothing lines result froma collaborative process between two people whoseem to share a vision and philosophy. Each designerworks independently to sketch his ideas before sharing them with the other. Then they inspect eachother’s sketches and find ways to combine their ideasand create something unique and cool.Academic Skills and Abilities Sketching and drawing Drafting Collaboration and teamwork Textiles, fabric, and clothing Business administrationCareer PathwaysDegree programs in fashion design are offered atthe Associate’s and Bachelor’s levels at many colleges and design schools. Some fashion designersalso pursue a degree in business, marketing, or fashion merchandising, especially those who want torun their own business or retail store. In addition tobasic design courses, human anatomy, mathematics, and psychology are also useful.Go to glencoe.com for this book’s OLC to learnmore about Proenza Schouler.525Frazer Harrison/Getty Images

15.1Types of Joints, Welds,and SymbolsPreview Drafters must understand basic welding principles to be able to incorporate welds indesigns. How do you think fusion welding works?Content Vocabulary welding groove weld fillet weld plug weld slot weld fusion welding gas welding arc welding gas-and-shielded-arcwelding intermittent weldAcademic VocabularyLearning these words while you read this section will also help you in your other subjects and tests. combination ignitionGraphic OrganizerUse a table like the one below to organize notes about welding.Types of WeldsTypes of JointsFusion Welding MethodsGo to glencoe.com for thisbook’s OLC for a downloadableversion of this graphic organizer.Academic StandardsEnglish Language ArtsRead texts to acquire new information (NCTE)MathematicsMeasurement Understand measurable attributes of objects and the units, systems, andprocesses of measurement (NCTM)SciencePhysical Science Chemical reactions; interactions of energy and matter (NSES)Science and Technology Abilities of technological design (NSES)Industry StandardsADDA Section 13Welding Drafting (ASME/ANSI B31.1; ASME/ANSI B31.3, ASME/ANSI 31.9)526Chapter 15 Welding DraftingNCTE National Council ofTeachers of EnglishLanguage ArtsNCTM National Councilof Teachers ofMathematicsNSES National ScienceEducation StandardsADDA American DesignDrafting AssociationANSIAmerican NationalStandards InstituteASME American Society ofMechanical Engineers

Types of Joint and WeldsWhat specific facts must you know aboutthe welding process when you draw partsto be welded?Welding is the process of joining metalparts together using heat (fusion welding)or a combination of heat and pressure(resistance welding). It has become a majorassembly method in industries that use steel,aluminum, and magnesium to build cars,trucks, airplanes, ships, and buildings. Weldedsteel parts for industrial use are generallylighter, stronger, and longer lasting than partsmade by other methods. See Figure 15-1Afor a pulley housing made by casting. Compare it with the similar part made by welding(see Figure 15-1B).Welding is not the best method for joining parts that require quick assembly and disassembly. In such cases, bolts or screws, or acombination of fastening methods might be abetter choice.A drafter drawing the parts to be weldedworks with a design engineer who knowswhat types of welding to use with different metals. Nevertheless, the drafter must befamiliar with the various welding processes aswell as their associated drafting symbols.Identify What are the advantages ofwelded steel parts?Industrial processes require a variety ofjoints and welds, because welding is used forso many different purposes. Various types ofjoints and welds can be combined in manydifferent ways to achieve the strength andcharacteristics desired for each application.Complete specifications for a weld mustinclude both the type of joint to be achievedand the type of weld to use.ABPULLEY .38PULLEY HOUSING.122XØ.801.009.00EXAMINE WELDING SYMBOLS2.506.002.502.381.004.252.00 .00.623.25.50Section 15.1 Types of Joints, Welds, and Symbols5273.261.00Ø.44Figure 15-1Pulley housing made by casting (A) and by welding (B)

JointsWeldsSee Figure 15-2 for an illustration of thefive basic joints used in welding: butt joints corner joints T-joints lap joints edge jointsThe proper weld for a particular job dependson the type of material specified, the tools tobe used, and the preparation cost. The following describes some basic welds:To decide on the correct joint, the designermust be familiar with the specified materialsprocesses, and the conditions of each. A groove weld is located in a groove ornotch in the work material. The grooves areclassified according to their shape (seeFigure 15-3). Although the welds in thatfigure are applied to a butt joint, they canalso be applied to any other joint. Notethat the grooves may be single or double.BUTT JOINTSINGLE SQUAREDOUBLE SQUARESINGLE VDOUBLE VSINGLE BEVELDOUBLE BEVELSINGLE UDOUBLE USINGLE JDOUBLE JCORNERJOINTT-JOINTLAP JOINTEDGE JOINTFigure 15-3Figure 15-2Five basic types of welded joints528Chapter 15 Welding DraftingTen basic types of groove welds applied to a buttjoint

PLUG WELDSFILLET WELDSSLOT WELDSFigure 15-4Plug, fillet, and slot welds Similar to a groove weld, a fillet weld rests on top of the joint. See Figure 15-4 foran example of a fillet weld.A plug weld fits into a small hole in thework material (see Figure 15-4).Similar to a plug weld, a slot weld has anopening that is a slot. The weld symbol forslot and plug welds is the same.Compare and Contrast What are thesimilarities and differences between a plugweld and a slot weld?Fusion WeldingWhy do you need two elements for fusionwelding?Fusion welding applies heat to create aweld. Fusion welding includes the gas, arc,thermit, and gas-and-shielded-arc processes.Although called by their separate names, soldering and brazing are also forms of fusionwelding.Fusion welding uses a welding filler material in the form of a wire or rod. The welderheats the material with a gas flame or a carbonarc. When the material melts, it fills in a jointand combines with the metal being welded.A combination of gases is used to create theheat for gas welding. This process was developed in 1885, when two gases—oxygen fromliquid air and acetylene from calcium carbide—were used. Burning acetylene supported byoxygen produces temperatures of between5000 and 6500 F (2760 and 3595 C).In 1881, de Meritens in France first performed a process known as arc welding,a form of fusion welding in which an electric arc forms between the work (part to bewelded) and an electrode. The arc causesintense heat to develop at the tip of theelectrode. This heat melts a spot on thework and on a rod of filler material, fusingthe two.The natural chemical reaction of aluminum with oxygen forms the basis for thermitwelding in which a mixture, or charge, madeof finely granulated aluminum and ironoxide is ignited by a small amount of specialignition powder. The charge burns rapidly,producing a very high temperature. This meltsthe metal, which then flows into molds andfuses mating parts.Aluminum, magnesium, low-alloy steels,carbon steels, stainless steel, copper, nickel,and titanium are some of the metals thatcan be welded using gas-and-shieldedarc welding. As its name implies, this process combines arc welding and gas welding.Two forms of gas can be used: tungsten-inertgas (TIG) and metallic-inert gas (MIG). In TIGwelding, the electrode that provides the arcfor welding is made of tungsten. Because itprovides only the heat, some other materialmust be used for filler. In MIG welding, theelectrode contains a consumable metallic rod,providing both the filler material and the arcfor fusion.Symbols for Fusion WeldingDrafters use special symbols establishedby the American Welding Society to specifywelds on a welding drawing. See Figure 15-5for an example of the use of welding symbolsused on a machine drawing. In Figure 15-6,they are used on a structural drawing.Refer to Figure 15-7 on page 531 for adescription of the standard welding symbolsapproved by the American Welding Society.The notes in the illustration explain howto place symbols and data in relation tothe reference line. By combining the symbols in Figure 15-7, you can describe anywelded joint, from the simplest to the mostcomplex.Section 15.1 Types of Joints, Welds, and Symbols529

BACKBASEContrast What is the primary differencebetween gas welding and arc welding?RIBStandard SymbolsThe distinction between the terms weldsymbol and welding symbol should be understood. The weld symbol, illustrated in Figure15-7, indicates the type of weld. The weldingsymbol is a system for representing a weld ondrawings. It includes not only the symbol butalso supplementary information and consistsof the following elements:.38.25.38BRACEFigure 15-5The application of weldingsymbols on a machine part1212—2ABCOL. D1COL. D24(LEFT OF D1)12 CB 271 —112 X 6 —2X 4FACE C EAST315—16ba12—2AB4ba-D ab-D82 4C15'-104315'-11 —BA8715'-5 —87 FIN16'-11 —5—161—4bbaabbha1—23—163111'-0 —8ab-BFINBENDLINE12—4R3—815—3 1671'-1—837—41—218—443EL. 17'-6 —H.P.FLOOR3—412'-5 —43—8FIN (SHAFT)530Chapter 15 Welding Drafting8ca1—41—433 36The application ofwelding symbols on astructural drawing31—121'-0Figure 15-647Ø—Ø HOLES FOR8ANCHOR BOLTS1'-21—45—162123134ha1 —212—2bbaaR12 —416'-11 —2412—21232—12—88—4Rha3—16STRIP LTHIS SIDE

BASIC WELD SYMBOLSFILLET PLUG STUD SPOT SEAMBACKSURFACFLANGEORORORINGSLOTPROJECBACKINGEDGE CORNER SQUARE SCARFTIONCONTOUR SYMBOLUJFLARE- FLAREVBEVELFIELD WELD SYMBOLS(E)FAR(N)BASIC WELD SYMBOLOR DETAIL REFERENCENUMBER OF SPOT, STUD,OR PROJECTION WELDSARROW SIDE OTHER SIDEDEPTH OF PREPARATION OR SIZEOR STRENGTH FOR CERTAIN WELDSBOTH SIDESGROOVE WELD SIZETAILREFERENCE LINEBEVELLENGTH OF WELDGROOVE ANGLE; INCLUDED ANGLEOF COUNTERSINK FOR PLUG WELDSTVROOT OPENING; DEPTH OF FILLINGFOR PLUG AND SLOT WELDSFINISH SYMBOLSPECIFICATION, PROCESS,OR OTHER REFERENCEGROOVE WELDSWELD-ALL-AROUND SYMBOLARROW CONNECTING REFERENCE LINETO ARROW-SIDE MEMBER OF JOINT ORARROW SIDE OF JOINTL–PPITCH (CENTER-TO-CENTER SPACING) OF WELDSELEMENTS IN THIS AREA REMAIN AS SHOWNWHEN TAIL AND ARROW ARE REVERSEDSUPPLEMENTARY SYMBOLSBACKING OR BLEINSERT(SQUARE)MELTTHROUGHWELDALLAROUNDFIELD WELDNOTE: SIZE, WELD SYMBOL, LENGTH OF WELD, AND SPACING MUST READ IN THAT ORDER FROM LEFT TO RIGHT ALONG THEREFERENCE LINE. NEITHER ORIENTATION OR REFERENCE LINE NOR LOCATION ALTER THIS RULE. THE PERPENDICULAR LEGOR FILLET, BEVEL, J, OR FLARE-BEVEL WELD SYMBOLS MUST BE AT LEFT. ARROW- AND OTHER-SIDE WELDS ARE OF THESAME SIZE UNLESS OTHERWISE SHOWN. SYMBOLS APPLY BETWEEN ABRUPT CHANGES IN DIRECTION OF WELDINGUNLESS GOVERNED BY THE "ALL-AROUND" SYMBOL OR OTHERWISE DIMENSIONED.Figure 15-7Weld symbols reference linearrowbasic weld symboldimensions and related datasupplementary symbolsfinish symbolstailspecifications, process, or other referencesNot all elements of a welding symbol needbe used. Use only those that are needed todescribe the weld clearly and completely.A welding symbol includes informationabout not only what type of weld to use butalso where on the joint to place the weld.See Figure 15-8 for five typical groovewelds and the symbol for each. The symbolSection 15.1 Types of Joints, Welds, and Symbols531

WELDcan be drawn on either side of the joint asspace permits. Note: When drawing a fillet,bevel, or J-grooved weld symbol, place theperpendicular leg of the symbol to the left(see Figure 15-9).An arrow leads from the symbol’s referenceline to the joint. The side of the joint to whichthe arrow points is called the arrow side. Theopposite side is called the other side. If the weldis to be on the arrow side of the joint, draw thetype-of-weld part of the symbol below the reference line (see Figure 15-10A and D). If theweld is to be on the other side, draw the typeof-weld part of the symbol above the referenceline (see Figure 15-10B and E). If the weld isto be on both sides of the joint, draw the typeof-weld part of the symbol both above andbelow the reference line (Figure 15-10C).When the weld is to be a J-grooved weld, youmust place the arrow from the welding symbolcorrectly to avoid confusion. For example, inFigure 15-11A, it is not clear which piece is tobe grooved. In Figure 15-11B, the arrow hasbeen redrawn to show clearly that the verticalpiece is to be grooved as in Figure 15-11C. Thedrawing in Figure 15-11D calls for two welds.The symbol below the reference line includesa J-grooved weld on the arrow side. The arrowshows that the horizontal piece is to be grooved.The symbol above the reference line indicatesa fillet weld on the other side. The drawing inFigure 15-11E shows how the completedwelds would look.In Figure 15-12A, the reference dimensions have been included with the weldingSYMBOLSQUARE.12DOUBLE SQUARE.12SINGLE VSINGLE BEVELSINGLE UFigure 15-8Symbols for five typical groove weldsFigure 15-9The perpendicular leg on aweld symbol is always drawnto the left.LEGFILLETJ-GROOVEDBEVELAFigure 15-10Weld symbolsshow the arrowside, the otherside or both CDBOTH SIDESSYMBOLChapter 15 Welding DraftingEWELDARROW SIDEOTHER SIDE

FILLETCORRECTNOT CLEARINCORRECTCORRECTABCDEFigure 15-11Weld symbols for the J-grooved weldFIELD D IN FIELD45 20 .50Figure 15-122.00-6.00.50.75 1.25.38Weld symbols and specificationsAsymbols. The joint in Figure 15-12B is madeaccording to the reference specifications inFigure 15-12A. This joint can be described asa double filleted-welded, partially grooved,double-J T-joint with incomplete penetration.The J-groove is of standard proportion. Theradius R is .50″ (13 mm), and the includedangle is 20 . The penetration is .75″ (19 mm)for the other side and 1.25″ (32 mm) deep forthe arrow side. There is a .50″ (13-mm) filletweld on the arrow side and a continuous .38″(10-mm) fillet weld on the other side. The fillet on the arrow side is 2.00″ (50 mm) long.The pitch of 6.00″ (150 mm) indicates that itis spaced 6.00″ (150 mm) center-to-center. Allfillet welds are standard at 45 .Bin Figure 15-12A. This indicates that thecontour of this weld is to be flat faced andunfinished. A convex contour symbol isover the .38″ (10-mm) fillet weld on thesame reference line. This symbol indicatesthat this weld is to be finished to a convexcontour. Figure 15-7 shows the supplementary welding symbols to be used for finishedwelding techniques.Define What does a solid black dot or blackflag symbol indicate?Dimensioning WeldsSupplementary SymbolsNotice the solid black dot on the elbow ofthe reference line in Figure 15-12A. This dot(or a black flag) is a supplementary symbol fora field weld. Both indicate that the weld is tobe made in the field or on the constructionsite rather than in the shop.The specification A2 is in the tail of the reference line in Figure 15-12A. This means thatthe work is to be a metal-arc process that usesa high-grade, covered, mild-steel electrode;the root is to be unchipped and the weldsunpeened, but the joint is to be preheated.Notice the flush contour (outline) symbolover the .50″ (13-mm) fillet weld symbolSee Figure 15-13 for the typical dimensions for a butt joint with a V-grooved weld.Typically, the manufacturer needs to knowthe required angle of the joint preparation (A),the root opening (R), and the height of reinforcement (C), specified only if a back or backing weld is to be used on the underside of thewelded joint. Dimensions for a T-joint with abevel-grooved weld include the bevel angle(B), the root opening (R), and the height ofreinforcement (C) if a weld is to be applied tothe underside of the joint (see Figure 15-14).See Figure 15-15 for the U-grooved jointpreparation for a butt joint. This joint type isexpensive to prepare and is used mainly forSection 15.1 Types of Joints, Welds, and Symbols533

AA"V"R.25CCRRFigure 15-13Dimensions for a V-grooved weld. A 60 minimum; C 0 to .12″; R .12″ to .25″; stock .50″ to .75″ thickFigure 15-15Dimensions for a U-grooved weld. A 45 minimum; C .06″ to .20″; R 0 to .56″BB"J"BEVELCCRRFigure 15-14Figure 15-16Dimensions for a bevel-grooved weld. B 45 minimum; C 0 to .12″; R .12″ to .25″Dimensions for a J-grooved weld. B 25 minimum; C .06″ to .20″; R 0 to .56″joining materials at least 1.00″ thick. In thiscase, dimension the groove angle (A), theradius (R) at the bottom of the groove, theroot opening (R), and the height of reinforcement (C), if applicable. The J-grooved jointpreparation is generally used on a T-joint(see Figure 15-16). This joint type requirespreparation on one part only, as shown, andclosely resembles the U-grooved joint. Like theU-grooved joint, it is used when joining materials at least 1.00″ thick.When the design engineer determines thatit is not necessary to run a weld the entirelength of the joint the length of the weld isgiven to the right of the weld symbol (seeFigure 15-17). A series of two or more shortwelds along a joint, called an intermittentweld, is specified and dimensioned as inFigure 15-18. The pitch (center-to-centerspacing) of intermittent welds is shown as534R.50Chapter 15 Welding Drafting16.002.00JOINT DESIGNLENGTH OF WELD2.00.2516.00DRAWING CALLOUTFigure 15-17Dimensioning the length of a weld.25

PITCH.3112.00LENGTHOF WELDPITCH12.00.31.312.00 – 12.002.00 – 12.00.312.002.002.00JOINT DESIGNLENGTHOF WELDFigure 15-18DRAWING CALLOUTSpecifying intermittent weldsTemperature ConversionsProcesses such as welding, forging, casting,soldering, and brazing, often involve numerical values for the high temperatures neededin these processes. It is often necessary fordrafters, engineers, and welders to work bothin degrees Fahrenheit (F) and in degreesCelsius or centigrade (C). Conversion fromone system to another can be accomplishedusing two simple formulas.Convert 8000 Fahrenheit to degrees Celsius.Convert 2975 Celsius to degrees Fahrenheit.To convert temperaturesfrom degrees Fahrenheit to degrees Celsius,use the formula:C 5 (F 32)9Example: Burning acetylene gas supported byoxygen for gas welding and brazing, temperatures between 5000 and 6500 Fahrenheit canbe achieved. These temperatures in Celsius or centigrade are 2760 and 3593 , respectively.To apply this formula to the lower limit oftemperatures for gas welding and brazing, plugin the numbers as follows:5C 9 (5000 32)5C 9 (4968)4968C 5 9C 2760 To convert temperatures from degrees Celsiusto degrees Fahrenheit, use the formula:F 5 9 C 32To convert the lower limit of temperatures forgas welding and brazing from Celsius to Fahrenheit, use the formula as follows:2760F 9 325Academic StandardsMathematicsMeasurement Understand measurable attributesof objects and the units, systems, and processes ofmeasurement (NCTM)24,840F 325F 4968 32F 5000 For help with this math activity, goto www.glencoe.com for this book’sOLC and click on Math Handbook.Section 15.1 Types of Joints, Welds, and Symbols535

LENGTHOF WELDPITCH12.00.31.31 2.00 – 12.00.31 2.00 – 12.0012.006.002.00.312.0012.0012.00JOINT DESIGNDRAWING CALLOUTFigure 15-19Staggered intermittent weldsthe distance between centers of incrementson one side of the joint. It is shown to theright of the length dimension with a hyphenSection 15.1 AssessmentAfter You ReadSelf-Check1.2.3.4.List and describe four different welds.Explain the welding process.Describe the fusion welding process.Determine the appropriate joint preparation for a specific weld application.between the two dimensions. Staggered intermittent welds are shown with the weld symbols staggered (see Figure 15-19).Drafting Practice6. Make a three-view drawing of the leverstand shown in Figure 15-20. Determine your own dimensions. Providea support rib for the upright member. Include dimensions and weldingsymbols.Academic Integration5. Convert Temperatures Make thefollowing conversions: 3500 C, 212 C,and 1200 C to Fahrenheit; and 4200 F,32 F, and 6000 F to Celsius.UPRIGHT.75 X 2.50 X 4.00BASE.75 X 2.50 X 4.00MeasurementReview this chapter’s Do the Math activityfor the conversion formulas.RIBLEVER STANDFigure 15-20Go to glencoe.com for thisbook’s OLC for help with thisdrafting practice.536Chapter 15 Welding Drafting

15.2Producing a Welding DrawingConnect Now that you have grasped the theory of welding, you will apply the principles youhave learned to an actual drawing. What aspect of hands-on work interests you most, and whichdo you find most challenging?Content Vocabulary weldmentAcademic VocabularyLearning these words while you read this section will also help you in your other subjects and tests. exemplifies significantlyGraphic OrganizerUse a chart like the one here to organize notes about steps in creating a welding drawing using boarddrafting and CAD techniques.Steps in Creating a Welding DrawingBoard DraftingGo to glencoe.com for thisbook’s OLC for a downloadableversion of this graphic organizer.CAD1.1.2.2.3.3.4.4.5.5.Academic StandardsEnglish Language ArtsNCTE National Council ofTeachers of EnglishLanguage ArtsRead texts to acquire new information (NCTE)MathematicsMeasurement Understand measurable attributes of objects and the units, systems, andprocesses of measurement (NCTM)ScienceNCTM National Councilof Teachers ofMathematicsNSES National ScienceEducation StandardsADDA American DesignDrafting AssociationPhysical Science Chemical reactions; interactions of energy and matter (NSES)Science and Technology Abilities of technological design (NSES)ANSIIndustry StandardsASME American Society ofMechanical EngineersAmerican NationalStandards InstituteADDA Section 13Welding Drafting (ASME/ANSI B31.1; ASME/ANSI B31.3, ASME/ANSI 31.9)Section 15.2 Producing a Welding Drawing537

In some cases, changing round featuresBoard-DraftingTechniquesWhat should you consider when preparinga welding drawing, to save a manufacturer“tooling up” time?on the casting to square, flat, or rectangular parts on the weldment reduces jointpreparation. This concept will becomeevident as you continue to convert theconnecting link.Because a weldment consists of severalindividual parts welded together to form anassembly, it is useful to number the partson the welding drawing and prepare a partslist. This saves the manufacturer considerable time in the “tooling up” process.Select appropriate weld joints and jointpreparations based on the size of the partsto be joined and strength required. In thiscase, you can use fillet welds throughoutwith no special joint preparation.A qualified engineer generally determinesthe size and type of weld to be specified.In this exercise, the engineer has suggested.19″ fillet welds throughout the part. You should now be ready to develop awelding drawing with dimensions and symbols. The information given on the completeddrawing should be sufficient to manufacturethe part. To make this experience more meaningful, the casting of the connecting link(see Figure 15-21) will be converted into aweldment.In the conversion process, consider severalthings: When you convert from a casting to aweldment, you can generally reduce thethickness of cast members by 1 materialthickness. For example, the ribs on thecasting are .38″ thick. Because steel plate isconsiderably stronger and tougher than castiron, the thickness of the replacement steelplate can be .25″ thick. This exemplifiesthat careful engineering and good judgmentare critical parts of the conversion process. To create the welding drawing, follow thesesteps:1. Consider the changes required or enabledby converting the connecting link from acasting to a weldment.389.00.062.50R.50O1.0051.0032.50O .444 1.2501.503.00Figure 15-21Connecting link casting538Chapter 15 Welding Drafting

2. Sketch the necessary views, including dimensions and welding symbols,to determine the appropriate scale anddrawing sheet size.3. Create an instrument drawing of the connecting link, incorporating all changesyou determined in step 1.4. Add the appropriate dimensions andwelding symbols.5. Number the parts on the welding drawing and create a parts list.Explain Why can the thickness of steelplate be less than that of cast iron for thesame part?CAD TechniquesHow can you use a symbol library increating a welding drawing?The procedure for creating a welding drawing using CAD is similar to that for creating any other CAD drawing. (You must, ofcourse, apply the welding theory discussed inthis chapter). The feature that sets the CADtechniques apart from board drafting techniques is the use of symbol libraries for thewelding symbols. As in other drafting applications, using a library for welding symbolsgreatly reduces the time and effort required tocreate a welding drawing.Figure 15-22 shows the finished weldingdrawing. Notice that by converting the roundfeatures on the casting to square features onthe weldment, you are able to reduce jointpreparation and fitting time significantly.This process greatly reduces the cost tomanufacture the part. Notice also that allparts except Part No. 5 are stock materials thatneed only be cut to length, placed in position,and welded. Therefore, relatively little specialcutting and fitting are required.Figure 15-22Welding drawing of the connecting linkfrom Figure 15-21QTYITEMMATLDESCRIPTIONPT NO.1SHAFTSTL2.00 X 3.0012SHAFTSTL4SUPPORTSTL.25 X 1.00 X 1.002RIBSTL.25 X 1.50 X 1.8842RIBSTL.25 X 3.00 X 3.3852RIBSTL.25 X 1.50 X 2.006.75 X 2.50239.001.75.03.062.50 .875 1.004.504X Ø.44.25 .75.503.19.621.001.75.87521.0052X O 1.0031.50.75O 1.250.753.50.252.001.25.1251.503.001.00.195.50O 2.00.25.1946.75.19.193.001.002.00Section 15.2 Producing a Welding Drawing539

As with other symbols, those for welds areavailable from a number of sources: thirdparty symbol libraries and standard symbollibraries preloaded on CAD systems. Bothvary in cost, and some third-party libraries areeven free.To use symbols that come on most versions of AutoCAD (see Figure 15-23), openthe DesignCenter and navigate to AutoCAD’sSamples folder and then to the DesignCenterfolder. The welding symbols consist of blocksin the Welding.dwg file. Pick the next toWelding.dwg. Pick Blocks to display the welding symbols. To use one of the symbols inyour drawing, just pick it and drag it into thecurrent drawing.Figure 15-23Open DesignCenter to usethe symbols in AutoCAD’swelding symbol library.540Chapter 15 Welding DraftingA typical drawing task a drafter encounters might be to convert the plan for a castinginto one for a weldment. Figure 15-21 showsa drawing of a casting for a connecting link.To convert this into a welding drawing, followthese steps:1. Study the bulleted list of considerationsfor converting a casting into a weldmentthat appears earlier in the chapter. Thenfollow these steps:2. Consider the changes required or enabledby converting the connecting link from acasting to a weldment.3. Determine the appropriate drawing sheetsize and the scale at which you will printthe finished drawing.

4. Start a new drawing file and create thetwo-view drawing of the connectinglink, incorporating all of the changesyou determined in step 1.5. Add the appropriate dimensions.6. Open a welding symbol library. Dragthe appropriate symbols from the symbol library into the connecting linkdrawing. Size and place the symbols asnecessary.7. Create the parts list. If the blocks inthe symbol library you are using haveembedded attributes, you may be able touse the attributes to create the parts listautomatically. See Chapter 11 for moreinformation about using blocks andattributes.Custom WeldingSymbolsIf you do not have access to a welding symbol library, it may be worthyour time to create one. Weldingsymbols are neither difficult nor timeconsuming to create. You can drawthem once, add custom attributesthat will make your parts list easier tocreate, and save the file for use in thisand other drawings.Drafting PracticeSection 15.2 AssessmentAfter You ReadSelf-Check1. Explain how to convert a drawing fora casting into an appropriate drawingfor a welded part.3. Prepare a drawing of each girder section shown in Figure 15-24 and placethe symbols for welding in appropriatelocations with dimensioning.114'-1 23161457Academic Integration57343316L334D114316x2171212-5 82. The topic sentence of a paragraphsometimes appears at the beginning.Sometimes it appears in the middleor at the end, and sometimes it is notdirectly stated, but must be inferred.Take notes from one of the sections byidentifying and writing down the keywords

must be used for fi ller. In MIG welding, the electrode contains a consumable metallic rod, providing both the fi ller material and the arc for fusion. Symbols for Fusion Welding Drafters use special symbols established by the American Welding Society to specify welds on a welding drawing. See Figure 15-5

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the welding processes most often used in today's industry including plasma arc cutting, oxyfuel gas cutting and welding, Gas Metal Arc Welding (GMAW), Flux-Cored Arc Welding (FCAW), Shielded Metal Arc Welding (SMAW), and Gas Tungsten Arc Welding (GTAW). Flat welding positions and basic joints will be practiced. Pipe and tube welding

3. Classification of Underwater Welding Underwater welding may be divided into two main types: a) Wet welding b) Dry welding Fig. 3.1 Classification of underwater welding 3.1 Wet welding 3.1.1. Wet welding with coated electrode Wet welding is performed at ambient pressure with the welder-diver in the water and no physical barrier

10.6 Braze-welding 460 Exercises 466 11 Joining processes (welding) 467 11.1 Fusion welding 468 11.2 Oxy-acetylene welding 468 11.3 Manual metal-arc welding 490 11.4 Workshop testing of welds 504 11.5 Miscellaneous fusion welding processes 506 11.6 Workholding devices for fusion welding 509 11.7 Resistance welding 515

Welding residual stresses and stress relieve Formation of the weld metal Solidification of the weld metal Phase transformations during welding Basics of welding methods used in welding of zirconium alloys TIC Laser Welding Electron Beam Welding Upset shape welding Resistance Appendix C -R

affected zone. Welding processes that are commonly used with the corrosion-resistant alloys are shown in Table 1. In addition to these common arc welding processes, other welding processes such as plasma arc welding, resistance spot welding, laser beam welding, electron beam welding, and submerged arc welding can be used. Because of

the limited depth of underwater welding. Welding equipment transformed from manual welding to underwater automatic welding. The efficient and low-cost underwater welding was achieved[7]. In order to study the automatic welding technology under larger deep-water environment, the underwater automatic welding system was designed in this paper. The