Achieve professional results with our ZrN-coated spiral router bits, engineered for precision. The ZrN coating enhances cutting performance by creating a harder, tougher edge, extending tool life, and providing resistance to wear. AMS-160-Z 8-Pc Set Includes: RB-102: High Precision Steel Router Collet Reducer 1/4 Overall Diameter x 1/8 Inner Diameter x 1 Inch Long Solid Carbide CNC Spiral O Flute Up-Cut Router Bits for Aluminum Cutting: 51406-Z: 1/8 Diameter x 5/16 x 1/8 Shank 51470-Z: 1/16 Diameter x 1/4 x 1/8 Shank 51480-Z: 1/4 Diameter x 3/4 x 1/4 Shank 51474-Z: 1/8 Diameter x 1/4 x 1/4 Shank 51454-Z: 1/8 Diameter x 1/2 x 1/4 Shank 51408-Z: 3/16 Diameter x 1/2 x 1/4 Shank 51402-Z: 1/4 Diameter x 5/8 x 1/4 Shank 51502-Z: 1/4 Diameter x 5/8 x 1/4 Shank Stored in a solid wood showcase storage box with a clear lid. Includes full color booklet. Wood storage box dimensions: 12" L x 6" W x 3" H. Please note: Never attempt to cut ferrous metals with these bits. Inspect cut quality and adjust feed / speed accordingly. For optimal results and to extend tool life when trimming/cutting aluminum use a mist lubricant system or air cooling.