Type U Drive Screws (also known as u-drive screws or hammer drive screws) are unslotted round head self-tapping screws used for making permanent fastenings in metal and plastics, such as securing nameplates in castings. They require a predrilled hole and can be installed with a hammer or mallet. The u-drive screw is designed with multiple start threads, a large helix angle and pivot. Steel drive screws shall produce mating threads without shearing of threads or fracture of the screw when driven into the proper sized hole in materials having a Rockwell hardness of B70 to B85. Stainless steel drive screws are not recommended for use in materials with a hardness greater than Rockwell B65. As a supplier of Type U drive screws, AFT carries a large selection of sizes and lengths. Please contact us with any questions or help finding a particular size or type.