Straight Brazed Finger Bit 1/2" shank Coarse. For routing stone with wood router 40/50 grit diamond, best on marble and softer granite Diameter of bit: 1/2" 1/2" Shank to be used on conventional routers. Use wet or dry. Water or other cooling agent is recommended for longer life of the bit. Total length: 3" Length of diamond: 1-1/2"