Trend IT/2031097 203Bk machine bit 18 mm diameter57.5mm overall lng. left handTungsten carbide tipped boring bit with centre point, two cutting edges and two spurs. Suitable for drilling hinge holes in natural wood and man-made boards (including paper/plastic coated and veneered). Boring bits have a cylindrical shank with flat and lng. adjusting screw. For use on automatic and point-to-point boring machines.Specification-D=18 mmOL=57.5 mmD2=10x26 mmL=55.5 mmRotation=Left hand