Milwaukee 48-32-1551 42 Piece S2 Impact Bit Set is engineered for extreme durability and ten times the life. Made from proprietary steel and heat treated to control hardness, these Impact Duty hammer drills feature an innovatively designed geometric shock absorption zone to extend their life. The forged tip provides a secure grip and maximum contact, eliminating stripping or slipping. This set offers a variety of driver bits for everyday use as well as rare applications. Made of premium S2 tool steel, this 48-32-1151 set is sturdy, built for heavy duty use.