Hex Head Thread Rolling Screws, Similar to DIN 7500 M4 in Bright Zinc Plated (BZP) Steel
Thread rolling screws are designed to tap their own threads into pre-drilled holes in light metals and steel. The triangular shaped tip design allows the thread rolling screw to cold form the female thread into the work piece, so there is no need to pre tap the hole. Thread rolling screws are defined in DIN 7500, but this standard does not mention this head type exactly, but this item conforms in every other respect.