Master Mechanic 27/64" x 5-3/8" High Speed Steel Black Oxide Drill Bit. With its 135 split point, jobber length, 3/8" shank, and a 135 point angle with 4 cutting edges, this drill bit eliminates walking and provides fast penetration. The black oxide tempering treatment reduces frictional resistance and improves chip flow, making it ideal for use in wood, plastic, wallboard, plywood, soft metals, aluminum, brass, and bronze. It can also be used occasionally in stainless steel and other hard metals. This bulk pack of drill bits is a great choice for professionals and DIY enthusiasts alike.