Freud 77-604 3/8" (Dia.) Three Flute Mortise Compression BitMortise Compression Spiral Bits feature a shorter up shear length than other compression spiral bits, making them ideal for grooves and mortises, or for through cuts in thin double sided material (5 8" thick or less). Rout plywood, melamine and other double sided materials, as well as hardwood and softwood. For use in CNC, hand held or table mounted routers. Perfect grooves and mortises in delicate materials Routs melamine, veneer plywood, hardwood