Spot Welding

Questions and Answers

High pressure holders are required at forces above 2400 lbs..  Tapers are no longer practical at these levels per RWMA Manual Fig 18.3. At these high forces the electrode tapers fail because they are continually forced deeper and deeper into the holder taper. High pressure holders use mechanical attachment that mount by means other than a taper and this is not an issue.

Electrodes are available in many sizes and shapes to fit most needs in industry. To choose many considerations come to mind. The first decision would be full size vs cap electrode. Are you a job shop or highly automated usually decides this.

Force is the "P" in PCT - Pressure Current and Time.The Force component of a weld schedule is required to hold the two work pieces being welded together during the welding operation. This prevents any arcing due to the parts being loose. If not held tightly molten material would be expelled during the weld operation. It also provides a forging action as the weld solidifies and cools. This forging action greatly improves the final weld strength.

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