Our left-hand jobber length drill bits are made from premium high-molybdenum steel for high strength and have a 135* split point for quickly sinked into hard metals without "walking". The precision ground flutes spiral in the opposite direction as standard drill bits making them ideal for removing broken studs and bolts. Made in the USA by Norseman Drill & Tool. This set goes from 1/16"-1/4" by 64ths and from 5/16"-1/2" by 16ths and contains 17 pieces.