Those seeking improved surface finishes in either plastics or hardwoods do well to move up to Amana Tool 3 flute low helix finishers. The unbeatable combination of three keen edges and a gentle 10º helix, equates to a stiffer tool that minimizes both part movement and edge burring, leaving a smooth finish.#51631, (D) diameter 1/4, (b) Cutting height 7/8, (D) shank 1/4, overall length (L) 3, flutes 3, 51631 Solid Carbide spiral finisher 1/4 dia x 7/8 x 1/4 shank Up-cut router bit