JESSOP CNSI is a high-carbon, high-chromium tool steel possessing outstanding resistance to wear. It air hardens with a minimum amount of distortion; it also may be oil hardened. Its analysis is balanced to give maximum hardness and toughness. It is recommended for general-purpose work where high wear resistance combined with shock resistance is needed. Its many applications include dies of many types, cutters, punches, brick molds, rolls, taps, knurls, forming tools and reamers. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-366. Producer or source: Jessop Steel Company.