Mill rolls Rolls for rolling mills Work rolls for multiple roll mills are usually made of Steels 9Х and 9Х2 tool medium alloy and high speed steels Work surface hardness as heat treated achieves HRC 61 66 Recent technologies use work rolls made of sintered carbide alloys tungsten carbide as a base more and more often Hard alloy roll manufacturing is based as a rule on hot pressing or sintering plasticized work pieces