This Faithfull HSSE M35 Cobalt Quick-Change Impact Drill Bit has the following specification: Tip Diameter: 4.0mm. Working Length: 43mm. Overall Length: 91mm. Pack Quantity: 1. Faithfull Cobalt Quick-Change Impact Drill Bits feature a revolutionary tip design that is far superior to any other drill bit in the industry. These innovative drill bits have 7 cutting edges and 3 peaks that offer several distinct competitive advantages: - Super-accurate self-centring - you can make a hole in a round-pipe with one hand. - Speed - twice as fast as split point drill bits. - Tool lifetime - up to 10 times longer life in mild steel. Manufactured from M35 HSSE grade steel with a 5% cobalt content for increased heat resistance. The cutting performance is fantastic, both on precision and degree of finish, leaving much less defects (burr) than other drill bits. Its protruding centre tip acts like a pilot drill, enabling super-accurate positioning and stops the drill from wandering. These bits are impact rated and have a 1/4in quick-change shank for use in impact drivers. Produced in accordance to DIN 338 and DIN 3126-E6.3, for high precision tolerances and geometric accuracy. Ideal for heavy-duty industrial work in alloy steels, carbon steels, cast iron, hardened alloy steels, stainless steels, high-temperature alloys, titanium alloy, high strength steel and carbon fibre composite materials.