Cobalt drill bits are designed to cut through extremely hard metals, including stainless steel, The Quick Cut Points are self-centering and penetrate faster with less pressure, It will not ""walk"" or ""wander"" at the starting surface, Extremely heat resistant, must be operated in power units that have a RPM speed of 1,500 or higher for maximum efficiency, Made from premium grade cobalt steel, 135 Split Point, starts cutting at the starting surface, For use in extremely hard metals, including stainless steel, No center punch needed, Aerospace NAS907-J specifications, Size: 7/16"", SKU: ISN15089