Master Mechanic, 15/64" x 3-7/8", high speed steel, BLACK oxide drill bit, 135 split point, jobber length, straight shank, 135 point angle with 4 cutting edges which eliminate walking & provide fast penetration, BLACK oxide tempering treatment reduces Frictional resistance & improves chip flow, recommended for wood, plastic, Wallboard, plywood & soft metals, aluminum, brass & bronze, for occasional use in stainless steel & other hard metals, Carded.