Spade bits are sometimes referred to as paddle bits. They are used for rough boring in wood because of their tendency to cause splintering when they emerge from the work-piece. They are flat, with a centering point and two cutters which are often equipped with spurs in an attempt to ensure a cleaner hole. Having small shank diameters relative to their boring diameters, spade bits shanks often have flats forged or ground into them to prevent slipping in drill chucks. Intended for high speed use, they are used with electric hand drills.