Our black & gold metric jobber length drill bits are made from highest quality high-molybdenum high-speed steel and are nitro-carburized for strength and long life. They feature a 135* split point which allows the drill bit to quickly sink into hard metals without "walking" eliminating the need for pilot drilling. The black & gold coating provides lubricity when cutting. Excelllent for drilling hardened steels and stainless steel. This set goes from M1-M13 by .5mm increments and has 25 pieces. Made in the USA by Norsemand Drill & Tool.