This circular slitting knife use for  corrugated cardboard slitter, The lifespan of circular knife is longer than common slitting knife. the edge of slitting knife has a mirror surface by high-precision grinding. We manufacture these ultra-thin, extremely sharp razor slitter knife blades from a wide range of materials for all conversion industries where this type of cutting is used. In circular razor or core slitting you need a sharp blade with an edge radius of 0.0025 to 0.005MM. ,OEM is Welcome.