Professional quality item with wide range of uses: M35 high speed steel drill bits with 5% cobalt for drilling stainless steel and reinforced steel materials. They can also be used for drilling metals and other materials such as cast iron, copper, high temperature alloys, titanium alloys, aluminum, hard plastics and woods, etc. Premium materials: M35 high speed steel with 5% cobalt. Durable and solid for longer service life. Drill bits are suitable for drilling heavy-duty metals including stainless steels, Cr-Ni and acid-resistant special steels. Heat resistant: High speed steel twist drill bits with cobalt should be used at 1,500 rpm or more for maximum efficiency. The straight shank provides a firm, precise grip and is compatible with standard chucks and regular round collets. Turned Design and Performance: Precise 135° slotted tip, gold oxide finish and straight round shanks. Prevents spillage, removes chips and particles faster. Fully precision ground product which ensures chips