63/64 Cobalt Reduced Shank Drill Bit with 1/2 Shank

63/64 Cobalt Reduced Shank Drill Bit with 1/2 Shank. Drill America D/ACO Cobalt Reduced Shank Drill are made of heat resistant m42 cobalt and ground to a heavy duty 135° split point. They are similar to high-speed steel but with more cobalt for improved performance when cutting harder metals such as stainless steel or nickel alloys.