Flat Wood Bits Specially designed hexagon shank and forged tripoint cutting head. Flat bit consists of: 13mm, 16mm, 20mm, 22mm, 25mm, 32mm and is suited particularly to the joinery trade. Particularly suitable for drilling hard and soft wood, plywood and particle board including MDF and chipboard. Twin spurs reduce the lifting of wood fibres leaving a cleaner hole. 6mm to 24mm Flat wood bits are 154mm long. 25mm to 40mm Flat wood bits are 160mm long.