HHIP 2006-0163 5/16 Inch HSS T-Slot Cutter Bolt Size 5/16; Cutter Diameter 21/32; Cutter Width 17/64; Neck Diameter 21/64 Shank Diameter 1/2; Undercut Length 39/64; Length 2-11/16 High speed steel .Tooth 8 Rugged design with free cutting features.; High speed steel Tooth 8