For most shredder applications SSI's standard cutter hardness is suitable. However, when certain applications require a harder, sharper edge, the cutters are hardfaced. This is done by welding alloys to the cutter edges.
SSI uses proprietary alloys to hardface their cutters. The alloys are rated up to a hardness level of HRC 58-66, with 61 being average. The advantage of hardfacing is that the cutter keeps its edge longer. And it is ideal for making clean cuts of ductile but abrasive materials such as tires, carpet, and nylon.
