This spade bit has a 1 4 inch hex shank system and it is best for use with portable power drills. The self cut speed spade bit performs extremely fast hole drilling. Its self feeding threaded tip enables the drill bit to effortlessly pull itself into the wood for high speed drilling with little exertion. Fast chip removal for rapid results is made possible by the specially shaped spade. In product tests, this drill bit produces holes 10 times faster than a standard spade bit. It is suitable for use on soft and hard wood, light building materials and plasterboard. Total length 400 mm bull extremely fast holes bull self cut speed spade bit performs extremely fast hole drilling bull self feeding threaded tip provides high speed drilling with little exertion bull fast chip removal and rapid results are made possible by a specially shaped spade bull in product tests, this drill bit produces holes 10 times faster than a standard spade bit specifications diameter d mm 18,00 total length l2 mm 400 materials wood materials in detail hard solid wood softwood chipboard