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, #45204, diameter (D): 1/4, cutting Height (B): 1/2, shank (D): 1/4, overall length (L): 2, flutes: 2, 45204 carbide Tipped straight plunge high production 1/4 dia x 1/2 x 1/4 inch Shank