Bosch cobalt bits offer the best heat resistance and a rigid thick web design for drilling in extremely hard and abrasive materials such as stainless steel, cast iron and titanium. A tough cobalt alloy withstands up to 1100°F for superior performance during extended periods of extreme heat. Overall bit hardness of 66-68 HRC allows these bits to penetrate the most resistant materials. Features a 135° split point that starts on contact with no walking or skating, eliminating the need for a center punch. Best used for drilling into light-gauge metal, high-carbon steel, aluminum and ally steel, cast iron, stainless steel and titanium.