Blade for Challenge 36 1/2" Diamond paper cutters, standard inlaid high speed steel (AKI-IV) by Alliance Knife Company. This blade measures 42" long x 4.000" high and .438" thick, with 12 holes. (Challenge I.D. is 8-142-1.) When ordering knives, please double-check the brand, model and serial number of your cutter, and measure your knife carefully.