Made In US, Heat Hardened, Replacement Blade For Blade Part # 406712, 165833, 175064, 189028. Craftsman, Poulan, Husqvarna Mulching blade for 21" mower, 21" long, 2-1/4" wide, .134" thick. 5/8" center mounting hole 3/8" outside holes, 1-7/8" C to C. Heat hardened steel for extended blade life. Made from premium grade high carbon steel Made In USA.