Weld Joints - Goodheart-Willcox

1 ObjectivesAfter studying this chapter, you will be able to: Identify different types of welds used withvarious Joints . Read and draw common welding symbols. Discuss advantages and disadvantages of differentweld Joints . List factors involved with joint TypesThe American Welding Society defines a joint as the manner in which materials fit together. As shown inFigure 6-1, there are five basic types of weld Joints : Butt joint . T- joint . Lap joint . Corner joint . Edge PreparationWeld Joints may be initially prepared in a number ofways. These include: Shearing. Casting. Forging. Machining. Stamping. Filing. Routing. Oxyacetylene cutting (thermal cutting process). Plasma arc cutting (thermal cutting process). preparation of the joint prior to welding will becovered in the chapters that detail the welding of TypesThere are various types of welds that can be made ineach of the basic Joints .

2 They include:Butt joint ,Figure 6-2. Square-groove butt weld . Bevel-groove butt weld . V-groove butt weld . J-groove butt weld . U-groove butt weld . Flare-V-groove butt weld . Flare-bevel-groove butt ,Figure 6-3. Fillet weld . Plug weld . Slot weld . Bevel-groove weld . J-groove weld . Flare-bevel-groove weld . Melt-through Jointsand weld Types666 CHAPTER57 ButtTLapCornerEdgeFigure five basic types of Joints used in joint ,Figure 6-4. Fillet weld . Plug weld . Slot weld . Spot weld . Bevel-groove weld . J-groove weld . Flare-bevel-groove joint ,Figure 6-5. Fillet weld . Spot weld . Square-groove weld or butt weld . V-groove weld . Bevel-groove weld . U-groove weld . J-groove weld . Flare-V-groove weld . Edge weld . Corner-flange joint ,Figure 6-6.

3 Square-groove weld or butt weld . Bevel-groove weld . V-groove weld . J-groove weld . U-groove weld . Edge-flange weld . Corner-flange WeldsIn some cases, a weld cannot be made from only oneside of the joint . When a weld must be made from bothsides, it is known as a double weld . Figure 6-7 showscommon applications of double welds in basic Metal Arc Welding HandbookFlare-bevelFlare-V J-grooveU-grooveButtBevel-grooveV-groove Figure of welds that may be made with a basic of welds that may be made with a basic of welds that may be made with a basic sample chapter is for review purposes only. Copyright The Goodheart-Willcox Co., Inc. All rights ConfigurationsThe basic joint often is changed to assist in acomponent s assembly.

4 A weld joint might be modified togain access to the weld joint or to change a weld smetallurgical properties. Some common weldmentconfiguration designs are described used in cylinder and head assemblies wherebacking bars or tooling cannot be used. See Figure application of joggle Joints is in the repair ofunibody automobiles where skin panels are placedtogether and welded. A built-in backing bar is used whenenough material is available for machining the requiredbacking or when tooling cannot be inserted (as in sometubular applications). An example in which tubing isbeing joined to heavy wall tube is shown in Figure Joints often use special backing rings or aremachined to fit specially designed mated parts.

5 Types ofbacking rings are shown in Figure 6-10. Figure 6-11shows a fabricated backing bar. These bars must fittightly or problems will be encountered in heat flow andpenetration. weld Joints specially designed for controlledpenetration are used where excessive weld penetrationwould cause a problem with assembly or liquid flow. Thistype of joint is shown in Figure 6 weld Joints and weld Types59 ButtFilletJ-grooveSpotV-grooveEdgeCorner flangeFlare-VFigure of welds that may be made with a basiccorner flangeEdge flangeFigure of welds that may be made with a basic -grooveBevel and filletFilletDouble filletFigure of double series of bead welds overlaid on the face of a jointis called buttering,Figure 6-13.

6 Buttered welds are oftenused to join dissimilar metals. A series of overlaid weldson the surface of a part to protect the base material iscalled surfacingor cladding. Refer to Figure 6-14. Welding Terms and SymbolsCommunication from the weld designer to thewelder is essential to proper completion of mostweldments. Some of the common terms used to describeparts of the weld joint are found in Figure 6-15. Other60 Gas Metal Arc Welding HandbookFigure types of backing rings for pipe butt weld with a fabricated backing weld penetration butt joint with a built-in backing weld joint welds, called surfacing or cladding,protect the base metal from wear or used to describe welds are given in Figure AWS welding symbolshown in Figure 6-17 wasdeveloped as a standard by the American WeldingSociety.

7 This symbol is used on drawings to indicate thetype of joint , placement, and the type of weld to be symbol may also include other information, such asfinish and contour of the completed is important to study and understand each part ofthe welding symbol. Figure 6-18 is a table showing basicweld symbolsthat are used with the AWS weldingChapter 6 weld Joints and weld Types61 Bevel angleRoot facethicknessGroove angleRoot openingRiserFigure joint toeWeld crownWeld toeRoot penetrationRootpenetrationWeld crownWeld throatLeg lengthLeg lengthFigure and weld area angle; included angle of countersink for plug weldsLength of weldPitch (center-to-centerspacing) of weldsField weld symbolArrow connectingreference line toarrow side member of joint or arrowside of jointWeld-all-around symbolNumber of spot, seam, stud,plug, slot, or projection weldsWeld symbolTail (may be omittedwhen referenceis not used)Specification, process, or other referenceDepth of bevel.

8 Size or strength for certain weldsGroove weld sizeRoot opening; depth of fillingfor plug and slot weldsFinish symbolContour symbolReference lineElements in this area remain as shown when tail and arrow are reversedWeld symbols shall be contained within the length of the reference lineTS(E) L-PFAR(N){{}}BOTH SIDESARROW OTHER SIDE SIDEF igure AWS welding symbol conveys specific and complete information to the welder.(Printed with permission of the American Welding Society)symbol to direct the welder in producing the proper weldjoint. The arrow of the welding symbol indicates thepoint at which the weld is to be made. The lineconnecting the arrow to the reference line is always at anangle.

9 Whenever the basic weld symbol is placed belowthe reference line, as shown in Figure 6-19, the weld ismade on the side where the arrow points (referred to asthe arrow side). Whenever the basic symbol is placedabove the reference line, the weld is to be made on theother side of the joint , as shown in Figure 6-20. Byplacing dimensions on the symbol and drawings, theexact size of the weld may be indicated. Study the62 Gas Metal Arc Welding HandbookGrooveSquareScarfVBevelUJFlare-V Flare-bevelFilletPlugorslotStudSpotorpro jectionSeamBackorbackingSurfacingEdgeFig ure weld symbols. (Printed with permission of the American Welding Society)DesiredweldArrow sideFillet weldsymbolFigure weld symbol shown on the bottom side of thereference line indicates that the weld is located where the sideFillet weldsymbolFigure weld symbol shown on the upper side of thereference line indicates that the weld is located on the oppositeside of the of typical weld symbols and weldments shownin Figure complete weld symbol gives the welderinstructions on how to prepare the base metal, thewelding process to use, and the finish for the completedweld.

10 Through careful use of these symbols, the welddesigner can convey all the information needed tocomplete a are offered that provide advanced study inthe area of print reading for welders. By taking suchclasses, the welder can improve his or her ability to readand interpret welding drawings. Studying texts on printreading is another method of gaining ability to read PositionsFor a welder, it is important to be able to weld indifferent positions. The American Welding Society hasdefined the positions of welding to include: Flat. Horizontal. Vertical. 6-22 demonstrates the four positions for filletwelds, grooved butt welds, and pipe welds. Whilepracticing welding in these positions, you should note howgravityaffects the molten weld pools.