Premium high-speed steel withstands extended drilling in tough materials. Black and gold oxide finish provide maximum corrosion resistance. 135-degree split-point tip starts drilling immediately with less force and eliminates “walking” across the work surface. Metal index case for easy bit access and identification. Includes drill bit sizes 1/16- to 1/2-inch in 1/64-inch increments. IRWIN® Tools Black and Gold High-Speed Steel Drill Bit, 29-Piece Set with Metal Index Case (3018005).