Solid Carbide single flute aluminum router bits, zirconium nitride (ZRN) coated, are especially designed to cut soft grades of aluminum sheet, (3003 grade) to achieve a satisfactory finished edge., #51452, direction Up-cut, (D) diameter 1/4, (b) Cutting height 1/4, (D) shank 1/4, overall length (L) 2, max RPM 28, 000, Recommended RPM 14, 000, flutes 1, 51452 Soft aluminum Cutting 1/4 dia x 1/4 x 1/4 shank Single flute Up-cut (up Shear) solid carbide ZRN coated