Also known as short-projection taps, these have fewer tapered threads at the tip than standard pipe taps, so you don't have to drive them as deep to produce full threads. They're made of high-speed steel and are for use on most metal and plastic. With a square shank, they're compatible with tap wrenches and tap holders for drill presses and milling machines. All have a bottoming chamfer with 1-2 chamfered cutting threads, so they can thread close to the bottom of closed-end holes.