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, #45452-CNC, diameter (D): 1-1/2, cutting Height (B): 1-1/4, Shank (D): 1/2, overall length (L): 2-7/8, max RPM: 18, 000, flutes: 2, 45452-CNC carbide Tipped straight plunge high production 1-1/2 dia x 1-1/4 x 1/2 inch Shank