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, #45210, diameter (D): 1/4, cutting height (B): 1, shank (D): 1/4, overall length (L): 2-1/4, flutes: 2, 45210 carbide Tipped straight plunge high production 1/4 dia x 1 inch x 1/4 shank.