Drill America #28 Cobalt Heavy Duty Drill Bit (Pack of 12), D/ACO Series

Cobalt steel tools are similar to high-speed steel, but with more cobalt for improved performance when cutting harder metals such as stainless steel or nickel alloys Gold oxide is a thinner oxide surface treatment than black oxide typically used to identify cobalt steel tools; performance is similar to uncoated tools Round shanks allow use with a wide variety of toolholding systems When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging Manufactured to National Aerospace standard 907