Spiral router bits are made by Amana Tool, the leading manufacturers of high quality wood cutting tools. Amana Tool 46460 SC Spiral Plunge with Corner Radius for Solid Wood 1/16 R x 1/4 Dia x 3/4 CH x 1/4 SHK 2-1/2 Inch Long Up-Cut Router Bit combines a shearing action in cutting with an augering action in chip clearance. The shearing action yields an especially clean & accurate cut, while the augering action clears chips from the cut. Excellent for: Aluminum, MDF, Soft/Hard Plastic, Soft/Hard Wood. SPECIFICATIONS: Direction: Up-Cut; (D) Diameter: 1/4; (R) Radius: 1/16; (B) Cutting Height: 3/4; (d) Shank: 1/4; Overall Length (L): 2-1/2; Flutes: 2.