Our black & gold drill bits in screw machine length are made from the highest quality high-molybdenum high-speed steel and are nitro-carburized for strength and long life. Screw machine length, also known as "stubby" drill bits, are shorter than standard drill bits allowing low clearance areas to be drilled. 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 1/16"-1/2" by 64ths and has 29 pieces. Made in the USA by Norseman Drill & Tool.