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, #45239, diameter (D): 3/16, cutting Height (B): 5/8, shank (D): 1/4, overall length (L): 2-3/16, flutes: 2, 45239 carbide Tipped straight plunge high production 3/16 dia x 5/8 x 1/4 inch Shank