Resistance Welding Pocket Handbook

Resistance Welding Pocket Handbook

1st Edition

Prepared by the American Welding Society (AWS) J1 Committee on Resistance Welding Equipment

With guidance from the AWS RWMA Committee

Under the Direction of the AWS Technical Activities Committee

Abstract

General information relating to the operation of common resistance welding equipment.

International Standard Book Number: 978-0-87171-785-6 American Welding Society

550 N.W. LeJeune Road, Miami, FL 33126

©2011 by American Welding Society All rights reserved

Printed in the United States of America

Photocopy Rights. No portion of this standard may be reproduced, stored in a retrieval system, or transmitted in any form, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner.

Statement of Use. Although care was taken in choosing and presenting the data in this pocket handbook, AWS cannot guarantee that it is error free. Further, this Pocket Handbook is not intended to be an exhaustive treatment of the topic and therefore may not include all available information, including with respect to safety and health issues. By publishing this Pocket Handbook, AWS does not insure anyone using the information it contains, against any liability or injury to property or persons arising from that use.

This booklet contains:

• basic information on resistance welding

• important “do’s” and “don’ts”

• common weld defects and their probable causes

• various charts including sample weld schedules

While this pocket handbook contains important safety tips, it is NOT a safety manual. Nor is it an operator’s manual or a maintenance manual. It cannot take the place of any of these. Similarly, it is not an industry standard and does not replace any existing industry standards. Its sole purpose is to help you make better and more consistent welds.

For additional information please consult other AWS technical documents relating to resistance welding. Assistance can also be obtained from the members of the RWMA Committee of the American Welding Society.

Table of Contents

What is a Resistance Weld? 5

Why Resistance Weld? 6

The Resistance Welding Processes 7

Spot Welding 7

Projection Welding 8

Seam Welding 9

Upset Welding (Butt Welding) 10

Flash Welding 10

Hot Upsetting 11

Resistance Brazing/Resistance Soldering 11

Resistance Parting 11

Resistance Heating 11

Machine Nomenclature 12

Rocker Welder 12

Press-Type Welder 13

Seam Welder 14

Upset or Flash Welder 15

Resistance Welding Guns 16

Resistance Welding Electrodes 18

Electrode Material Types 18

Spot Welding Electrode Shapes 20

Electrode Do’s. 21

Electrode Don’ts 22

Effect of Electrode Wear on Welding 24

Electrode Face to Body Diameter Guidelines 25

Importance of Water Tubes 26

Important Welding Hints 27

Weld Defects and Causes 29

Recommended Practices 31

Spot Welding Low Carbon Steel 32

Spot Welding Galvanized Low Carbon Steel 33

Spot Welding HSLA Steel 34

Spot Welding Aluminum 35

Projection Welding Low Carbon Steel 37

Seam Welding Low Carbon Steel 39

Flash Welding 40

Common Conversions 42

Other Documents on Resistance Welding 43

What is a Resistance Weld?

Electrode Force

Upper Electrode

It is the localized fusion of metal where the heat

Resistance to flow of electrical current generates heat quickly causing a weld

required for coalescence is caused by the flow of electric current through the workpieces and pressure is applied by the electrodes to forge the

parts together. An example resistance welding configuration is shown in Figure 1.

Faying Surface of Material to be Welded

Electrode Force

Lower Electrode

Figure 1—Basic Resistance Weld Configuration