welding representation

Welding Representation

Chapter 22

2Technical Drawing 13th EditionGiesecke, Mitchell, Spencer, Hill Dygdon, Novak, Lockhart

© 2009 Pearson Education, Upper Saddle River, NJ 07458.

All Rights Reserved.

Objectives

• Describe the various welding processes

• Draw the common welding symbols

• Dimension a welding drawing using standard ANSI welding notations




Objectives (cont.)

• Identify and draw a fillet weld, groove weld, back weld, spot weld, seam weld, projection weld, and flash weld

• Describe the use of welding symbols in CAD drawings




Welding Processes

• The principal methods of welding are:• Gas welding• Arc welding• Resistance welding




Standard Symbols

• Welding drawings are a special type of assembly drawing as weldments are composed of a number of separate pieces fastened together as a unit

• Joints are all shown as they would appear before welding




Weldment Drawing




Welding Symbols

• The items that can be specified in a welding symbol are:• Type of weld• Process• Depth of bevel, size or strength for

some weld types• Groove weld size• Finishing designator• Contour




Welding Symbols

• Cont.• Groove angle• Root opening• Length of weld• Number and pitch of welds• Whether the weld is to be field welded• All around indicator• Which side of the material is to be

welded




Basic Welds and Symbols




Types of Welded Joints

• There are five basic types of welded joints:• Butt joint• Corner joint• T-joint• Lap joint• Edge joint




Types of Welded Joints




Types of Welds

• There are four types of arc and gas welds:• Back or backing weld• Fillet weld• Plug or slot weld• Groove weld




Types of Welds

• The four basic resistance welds are:• Spot weld• Projection weld• Seam weld• Flash or upset weld




Welding Symbols

• The basic element of the symbol is the “bent” arrow• The arrow points to the joint where

the weld is to be made• Attached to the reference line, or

shank, is the symbol for the desired weld




Welding Symbols




Complete Welding Symbol




Fillet Welds

• The usual fillet weld has equal legs




Groove Welds




Back or Backing Welds




Surface Welds

• The surface weld symbol indicates a surface to be built up




Plug and Slot Welds




Spot Welds




Seam Welds




Projection Welds




Flash and Upset Welds

• Flash and upset weld symbols have no arrow-side or other-side significance




Welding Applications

• Welding is often cheaper when only one or a few identical parts are required

• Welding is also suitable for large structures that are difficult or impossible to fabricate entirely in a shop




Welding Templates

• Welding templates can simplify drawing welding symbols by hand

• They have all the forms needed for drawing the arrow, weld symbols, and supplementary symbols




Computer Graphics

• Welding symbol libraries available in CAD and allow for rapid application of accurate, uniform symbols that are in compliance with standards

welding representation

Documents

technical drawing

hill dygdon

pearson education

upper saddle river

weldment drawing

welding symbolscont

welding representationchapter

projection weld