This IRWIN 18-Piece Black Oxide Drill Bit Set includes drill bits with a black oxide surface to resist corrosion. The 135° split point helps prevent walking for smooth control. These powerful drill bits come in a durable rubber-sided case for added impact resistance, and the sliding latch design provides added security. The Pro Set case features a full-length metal hinge pin for durability and easy-to-read markings for quick drill bit identification.