Irwin 3016021 21/64" Cobalt HSS Jobber Length Drill Bit (5 Pack)

High speed steel with M-35, five percent cobalt, for higher heat and abrasion resistance; heavy duty web construction for strength and durability. Split point begins drilling immediately, minimizing bit walk when used in applications such as metal drilling, including heavy duty abrasive alloy metal drilling on hardened steel (heat-treated).