The 18° dovetail Bit is used with the Leigh jig., #45835, diameter (D) 1/2, angle (a°) 18°, cutting height (B) 0.415, shank (D) 1/4, overall length (L) 2-1/4, Type Leigh #128, flutes 2, Carbide Tipped Dovetail 18 deg x 1/2 dia x .415 x 1/4 inch shank