Plastic mold steel 4Cr13 steel is S136, American standard 420, German standard 1.2083 is a martensitic stainless steel. The steel has good machinability. After heat treatment, it has excellent magic corrosion resistance, polishing performance, high strength and Wear resistance, can be used to make parts with strong resistance to nitric acid and organic acid corrosion, chlorine-containing plastics with corrosive gases or plastic mold steel with flame retardants added