Use TCT for abrasive materials such as chipboard, MDF, plywood, hardwoods & hard plastics. Two flutes give a clean finish to cut edges. All cutters above & including 9.5 mm. diameter, have TCT plunge centre tips. D=15/64 inch. D=6 mm. C=16 mm. OL=48 mm. Shank Diameter=1/4 inch.