With the fast developing machine, both the screw rotation speed and the pressure in the barrel are increased, also with the very fast speed research and development of engineering plastic and modified plasic, the ordinary screw and barrel made of nitriding steel can’t meet the requirement of abrasion, corrosion and high temperature. Based on the actual requirement Jnha Factory has developed and introduced the materials which are fit for the modern plastic processing. And these materials have a lot of advantages, such as high precision, high hardness and high wear resistant and anticorrosion, Raw materials of Jnha Factory include alloy steel, stainless steel and CPM tool steels, The grades of materials are listed in the following chart, their properties and the relative document applied are summarized.