Pressure Or Welding Force
The pressure exerted by the tongs and the electrode tips on the workpiece has a great effect on the amount of weld current that flows through the joint. The greater the pressure, the higher the welding current value will be, within the capacity of the resistance spot welding machine. Setting pressure is relatively easy. Normally, samples of material to be welded are placed between the electrode tips and checked for adequate pressure to make the weld. If more or less pressure is required, the operating manual for the resistance spot welding machine will give explicit directions for making the correct setting. As part of the equipment set-up, the tong and electrode tip travel should be adjusted to the minimum required amount to prevent “hammering” the electrode tips and tip holders.