Abstract CYCLOPS M4 is a deep-hardening steel that was developed to utilize the excellent abrasion resistance that results from higher-than-normal carbon and vanadium contents in the molybdenum-tungsten family of high-speed steels. It is recommended for heavy-duty cutting operations and for sharp edges for fine cuts. Cyclops M4 should always be used at or near maximum hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-335. Producer or source: Cyclops Corporation.