CHAPTER 22 WELDING REPRESENTATION 1 IMPORTANCE OF THE

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CHAPTER 22 WELDING REPRESENTATION 1

CHAPTER 22 WELDING REPRESENTATION 1

IMPORTANCE OF THE DRAWING o Welding is used very extensively and for large variety

IMPORTANCE OF THE DRAWING o Welding is used very extensively and for large variety of purposes. It is essential to show accurate method of welding on working drawing. o To provide complete weld information on the drawing, a system of welding symbols was developed by ANSI. 2

Welding Processes • Arc welding (SMAW, Shielded Metal Arc Welding, GMAW Gas Metal Arc

Welding Processes • Arc welding (SMAW, Shielded Metal Arc Welding, GMAW Gas Metal Arc Welding, plus others…) • Resistance welding (RSW, Resistance Spot Welding, and others…) • Gas welding (OFW, Oxy Fuel Welding) RSW GMAW OFW An automobile frame is welded on a robotic automobile assembly line. (Courtesy of Vladimir Pcholkin/Stone/Getty images. ) 3

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Joints 5

Joints 5

25. 4 TYPES OF WELD Four basic types of Arc and Gas weld. o

25. 4 TYPES OF WELD Four basic types of Arc and Gas weld. o Back or backing o Fillet o Plug or spot o Groove 6

Basic Welds and Symbols 7

Basic Welds and Symbols 7

UNDERSTANDING A WELDING SYMBOL A welding symbol added to the drawing has many different

UNDERSTANDING A WELDING SYMBOL A welding symbol added to the drawing has many different features that specify each detail of the weld. The items that can be specified are: • Type of weld • Process • Depth of bevel, size, or strength for some weld types • Groove weld size • Finishing designator • Contour • Groove angle • Root opening • Length of weld • Number and pitch (center to center spacing) of welds • Whether the weld is to be field welded (done on site) • All-around indicator • Which side of the material is to be welded 8

Welding Symbols 9

Welding Symbols 9

Fillet Welds o The usual fillet weld has equal legs 10

Fillet Welds o The usual fillet weld has equal legs 10

Fillet Weld Length and Pitch TWO inch length of weld, with a FIVE inch

Fillet Weld Length and Pitch TWO inch length of weld, with a FIVE inch pitch (center-to-center). The. 25 represents the weld leg length. THREE inch length of weld, with a TEN inch pitch (center-to-center). The. 25 represents the weld leg length. 11

Surface Contour and Fillet Welds Fillet weld with a Convex Finish by Machining Fillet

Surface Contour and Fillet Welds Fillet weld with a Convex Finish by Machining Fillet weld with a Flush Finish by Grinding KEY: C= chipping G = grinding M = machining R = rolling H = hammering Fillet weld with a Flush Finish by Machining Fillet weld with a Flush Finish by Chipping 12

The Welding Symbol Tail Reference to a specification, process, or other supplementary information is

The Welding Symbol Tail Reference to a specification, process, or other supplementary information is indicated by any desired symbol in the tail of the arrow. Otherwise, a general note may be placed in the tail. If no reference is indicated in the symbol, the tail may be omitted. UNLESS OTHERWISE INDICATED, MAKE ALL WELDS PER SPECIFICATION NO. XXX Resistance Spot Weld an Electron Beam Weld are called out in the Tail of the Welding Symbols. 13

Welds extending completely around a joint are indicated by an open circle around the

Welds extending completely around a joint are indicated by an open circle around the elbow of the arrow. 14

FIELD WELD 15

FIELD WELD 15

Complete Welding Symbol 16

Complete Welding Symbol 16

J-GROOVE WELD 17

J-GROOVE WELD 17

Groove Welds 18

Groove Welds 18

BACK OR BACKING WELDS A back or backing symbol opposite the groove weld symbol

BACK OR BACKING WELDS A back or backing symbol opposite the groove weld symbol indicates bead-type welds used as back or backing welds on single-groove welds. Back or Backing Weld Symbols 19

PLUG AND SLOT WELDS The same symbol is used for plug welds and slot

PLUG AND SLOT WELDS The same symbol is used for plug welds and slot welds. If it is in the arrow-side member, place the weld symbol below the reference line If it is in the other-side member, place the weld symbol above the line A plug weld is understood to fill the depth of the hole unless its depth is indicated inside the weld symbol 20

SURFACE WELD Show the deposit of the weld at left side of the symbol.

SURFACE WELD Show the deposit of the weld at left side of the symbol. Since used for build up the surfaces not for joint, no arrow or other side, symbol always below. 21

25. 11 SPOT WELD 22

25. 11 SPOT WELD 22

SPOT WELDS The size of a spot weld is its diameter. If you need

SPOT WELDS The size of a spot weld is its diameter. If you need to indicate the minimum acceptable shear strength in pounds per spot, instead of the size of the weld, place this value at the left of the weld symbol. The pitch would be placed to the right of the weld symbol if needed. . 23

25. 12 SEAM WELDING 24

25. 12 SEAM WELDING 24

SEAM WELDS The seam weld symbol, with the welding process indicated in the tail,

SEAM WELDS The seam weld symbol, with the welding process indicated in the tail, The size of the seam weld is its width. Show this value at the left of the weld symbol, on either side of the reference line. If you need to indicate the minimum acceptable shear strength in pounds per linear inch, instead of the size of the weld, place this value at the left of the weld symbol, and show the length of a seam weld at the right of the weld symbol 25