Master Mechanic, 19/64" x 4-3/8" ,4341, High Speed Steel Black Oxide Drill Bit, 135 Split Point, Jobber Length, St Shank, 135 Point Angle With 4 Cutting Edges Eliminates Walking & Provides 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.