IRWIN 3016024 Jobber Drill Bit, Spiral Flute, 3-5/8 in L Flute, Straight Shank, 3/8 in Dia x 1-3/8 in L Shank           High-speed steel with M-35, 5% 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).