Pressure
The effect of pressure on the resistance spot weld should be carefully
considered. The primary purpose of pressure is to hold the parts to be
welded in intimate contact at the joint interface. This action assures
consistent electrical resistance and conductivity at the point of weld. The
tongs and electrode tips should NOT be used to pull the workpieces
together. The resistance spot welding machine is not designed as an
electrical “C” clamp! The parts to be welded should be in intimate
contact BEFORE pressure is applied.