Replaceable carbide knives to extend tool cutting life. Just replace the knives when dull or turn to sharper edge if applicable. Replaceable knives are as much as 4 times longer lasting than carbide tipped equivalent.. 1/4 Inch Shank SPECIFICATIONS: (D) Diameter: 1-1/2 (B) Cutting Height: 12mm (15/32) (d) Shank: 1/4 Overall Length (L): 1-11/16 Max RPM: 24,000 L1: 1-1/16 Replacement Knives: HMA-12 (2) (A) Cut Depth: 1/4 Surfacing, Planing Router Bits are made by Amana Tool, the leading manufacturers of high quality wood cutting tools. Amana Tool RC-2248 Mini Spoilboard Surfacing & Rabbeting Flycutter 1-1/2 D x 12mm (15/32) CH x 1/4 Inch SHK Insert Router Bit is engineered with an Amana-exclusive carbide grade for the highest quality of cut, maximum cutting efficiency, and faster material removal process. Excellent for: Fiberboard, HDF/LDF, MDF, Balsa Core, Plastic, Plywood/Chipboard, Solidwood/Softwood, Ultra-High-Molecular-Weight Polyethylene (UHMWPE). SPECIFICATIONS: (D) Diameter: 1-1/2; (B) Cutting Height: 12mm (15/32); (d) Shank: 1/4; Overall Length (L): 1-11/16; Max RPM: 24,000; L1: 1-1/16; Replacement Knives: HMA-12 (2); (A) Cut Depth: 1/4.