GTS 01-112 CryoCobalt Drill Bit (6.35mm) 1/4" 3 PackHarder Metal Drill Bits Drill Harder Metals Added cobalt increases the micro sharpness and allows the bits to drill metals up to 58Rc including hardened, high strength alloy steels Long Life Cryophile treatment improves drill bit flexibility and extends bit life Thicker Web Design provides extra strength needed for tough materials and reduces breakage GM and I CAR validated This is a 3 pack of drill bits