Alpen cobalt drill bit 9.00 mm. -Diameter: 9mm. -Self-centering due to its specially sharpened tip. -Tolerance up to 600º c. From thermal stress. -Due to its special sharpening, it allows easier drilling with a pressure of up to 50% lower than normal. -Suitable for construction steels, alloy steels, stainless steel, copper, brass, aluminum and plastic. -Made with cobalt, which is a very hard material, which provides great resistance to breakage and high temperatures.