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, #45198, diameter (D): 3/16, cutting Height (B): 7/16, shank (D):, /8, overall length (L): 1-1/2, flutes: 2, 45198 carbide Tipped straight plunge high production 3/16 dia x 7/16 x 1/8 inch Shank 2 Flute