Projection welding of a weld nut or weld bolt involves three phases. In the first phase, the projection is in contact with the mating sheet. Then the current starts to heat the projection to welding temperature. The electrode force then causes the heated projection to collapse rapidly, and fusion takes place.Tab projection weld nuts can feature single or multiple projections which facilitates a weld that is both strong and penetrating. These weld nuts are particularly well suited for use with heavier gauge materials and can be applied to flat or curved surfaces.
