POWERTEC High Speed Steel (HSS) Knives are made of premium High Speed Steel (HSS) with performance that meets or exceeds OEM product. The manufacturing process started with premium HSS material, followed by strictly professional machining and quality control that ensure extreme sharpness, precision, balancing and tight tolerance in every piece of in.POWERTEC HSS Knife in. product. The final Heat Treatment enhances the hardness and durability. in.POWERTEC High Speed Steel (HSS) Knives in. stay sharp and last longer than conventional product. We guarantee that in.POWERTEC High Speed Steel (HSS) Knives in. meet or exceed OEM quality and industrial standard. Replacement For Craftsman 21758, Delta TP305, Grizzly G0633, Wen 6550, Porter Cable PC305TP, POWERTEC PL1252.