Tapping screws are threaded fasteners with the ability to tap their own mating internal thread with driven into preformed holes in metallic and nonmetallic materials. Tapping screws are high strength, one piece, one side installation fasteners. Because they form or cut their own mating thread, there is generally a good fit which enhances resistance to loosening in service. Self-tapping screws remove the steps of pre-drilling and tapping from many building and machining projects. With an understanding of the appearance and application of different types of self-tapping screws, the engineer can choose the right one for each project.