Festool Twist drill bit HSS D4/43 - 4mm replacement HSS Spiral Drill Bit designed to be used with the Centrotec shank. The Centrotec shank can be used with all three-jaw chucks for no-slip performance or in conjunction with Festool's Centrotec chuck system. With the Centrotec design there is a better transfer of force with no chance for bit slippage or marring of the drill bit. Reduce the weight of the drill by nearly ½ pound and the length by nearly 1-1/2?ö with the Centrotec system. Centrotec Spiral Drill Bit are all precision ground and polished to provide you with a compact and durable solution for drilling wood, metal and plastic. Manufactured from HSS steel, which is high quality steel that stays sharp longer. Economically packaged in 10 piece pack.4mm replacement bit in a 10 piece pack for better savings.Manufactured from High Speed Steel for longer service life.Spur-less design with beveled chamfers that make the cleanest cuts possible.For use in wood, metal or plastic.Fits either Festool Centrotec chuck or standard chuck.