Use a Two-Flute bit where fine finish is paramount. Two flutes balance the bit, eliminating vibration that degrades the cut finish. Two cuts per revolution Yield a smooth surface, but feed rate is slightly reduced, #45181, diameter (D): 3/4, cutting height (B): 5/8, shank (D): 1/2, overall length (L): 2-1/4, flutes: 2, 45181 carbide Tipped straight plunge high production/ Mortising 3/4 dia x 5/8 x 1/2 inch shank