Blade for Challenge 37" 370 paper cutters, standard inlaid carbon steel (AKI-I) by Alliance Knife Company. This blade measures 44" long x 5.000" high and .431" thick, with 18 holes. (Challenge I.D. is 9-142.) When ordering knives, please double-check the brand, model and serial number of your cutter, and measure your knife carefully. There is a 15% restocking fee for returned knives due to customer error.