Master Mechanic 25/64" x 5-1/8" High Speed Steel Black Oxide Drill Bit. It has a 135 split point, jobber length, 3/8" shank, and 135 point angle with 4 cutting edges which eliminate walking and provide fast penetration. Black oxide tempering treatment reduces frictional resistance and improves chip flow. It is recommended for wood, plastic, wallboard, plywood, soft metals, aluminum, brass, bronze, and for occasional use in stainless steel and other hard metals. This bulk pack is a great value for the price.