115 Pc Cobalt Drill Bit Set. 10 x 6 x 4 inches. Cobalt steel bits last longer, cut faster than high speed steel. 29 fractional sizes: 1/16 in. 26 letter sizes: A-Z. 60 numbered wire gauges:1 to 60. Retains hardness at temperatures up to 1000° F. Each of these 115 cobalt drill bits comes organized in a metal indexed storage case for easy transport to your worksite. These cobalt drill bits retain their hardness up to 1000 degrees Fahrenheit making them ideal for drilling cast iron, heat-treated steel, stainless steel and other hard materials. With aggressive 135 degree tips, these cobalt drills bits not only last longer but also cut faster than standard high speed steel bits. We offer the best prices around on high quality products. Our E-store includes media such as books, movies, music and games while offering electronics, toys, sporting apparel, clothing, tools, general home, garden items and more. We are always working hard to ensure your package arrives as soon as possible. We do not accept P. Please provide a physical address. We try our very best to make sure every customer is completely satisfied. If there’s a problem, message us! We’re happy to help.