These high speed steel drill bits are fully ground with a 135° split point for precise centring to prevent drill wander. The black oxide coating ensures the drill bits are more durable and resistant to corrosion than standard HSS bits. Draper Black Series drill bits do not need to be used in conjunction with a cooling agent. Suitable for use with metal, wood, chipboard and plastic. Compatible with a standard 10/13mm chuck. Sizes 1.0-10.0mm. Supplied inside a metal case.