Q. Define spot welding electrodes
• To conduct the welding current to the work pieces.
• To transmit to the work pieces in the weld area the amount of force needed to produce a satisfactory weld.
• To dissipate the heat form the weld zone and thus prevent surface fusion of the work.
Requirements of spot Welding Electrodes
A spot welding electrode must
o Be a good conductor of electricity
o Be a good conductor of heat
o Have good mechanical strength and hardness at high temperatures.
o Have a minimum tendency to combine with the metal being welded.
APPLICATIONS OF SPOT WELDING
• Spot welding of two 12.5 mm thick steel plates has been done satisfactorily as a replacement for riveting.
• Many assemblies of two or more sheet metal stampings that do not require gas tight or liquid tight joints can be more economically joined by spot welding than by mechanical methods.
• Attachment of braces, brackets, pads or clips to formed sheet-metal parts such as cases, covers, bases or trays is another application of spot welding.
• Spot welding finds application in automobile and aircraft industries.