Blade for Polar 78E, ED, S&X New Style paper cutters, standard inlaid carbon steel (AKI-I) by Alliance Knife Company. This blade measures 37.795" long x 4.330" high and .461" thick. Standard inlaid carbon alloy tool steel is manufactured from a composite, inlaid material utilizing the traditional two-piece manufacturing system. The 1/8" thick alloy tool steel, laid into the soft backing material, provides sufficient rigidity and strength to ensure that AKI paper knives will withstand the extreme cutting pressures of high lifts and coated paper. (In many cases, high speed steel and tungsten steel knives are also available - call for pricing.) 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.