Tapping screws form mating threads in materials they are driven into. There are two basic types: thread forming and thread cutting. The thread-forming screw displaced material around the pilot hole so ...

Reed Rolled Thread Die Co. cylindrical die thread rolling machines ; thread rolling processing machines ; form and thread rolling dies ; thread rolling attachments ; knurls for automatic screw ...

Self-tapping screws are usually drilled into pre-made holes (pilot holes) in metals, such as zinc, aluminum, and bronze and its alloys, as well as plastics and resin-impregnated plywood. They create ...