Spot Welding

Questions and Answers

A weld schedule is an instruction to set up a resistance welder for a given job. It includes all of the specific settings of the machine, control settings, tools, electrodes, forces, times, rates and all other pertinent data related to a job. It also includes the information about the part, including material, thickness, number of welds, weld locations, quality requirements, and precleaning. This information is stored and can be used to set up the job on it’s next run. It also can be used as a ground zero if parameters have changed and you want to go back to when the job started.

Resistance welding over a lip, in a corner, or in a box might be a perfect application for a double bend electrode.

Double Bend Sketch

Above is a sketch showing an example of a double bend electrode welding in a tight area. There are many applications like this that a double bend full size electrode or double bend shank and cap will allow you to reach an otherwise difficult location to weld. Double bends can be water cooled to increase life.  Double bends come in many offsets and sizes as shown below.

bent electrodes2


Reference: RWMA - Resistance Welding Manual 4th Edition


Double Bend Sketch


Sometimes we have to reach inside a box or over a feature in a part that stretches our imagination. A double bend electrode might be the answer but a single bend electrode might also get us that extra distance. Both can be water cooled and deliver good force into restricted areas.

bent electrodes2

Reference: RWMA - Resistance Welding Manual 4th Edition



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.

 Pneumatic Cylinder

           AIR CYLINDER

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