Which steel is suitable for PET preform molds?

For PET (Polyethylene terephthalate) preform molds used in injection molding processes, several types of tool steels are commonly considered suitable due to their characteristics that cater to the demands of the molding process. The choice of steel depends on various factors such as production volume, required precision, and expected tool life. Here are some tool steels commonly used for PET preform molds:

P20 Steel (1.2311 or 1.2738): P20 is a versatile, low-alloy tool steel with good toughness and machinability. It's widely used in injection molds for its excellent polishability, dimensional stability, and relatively lower cost compared to other tool steels. P20 steel can provide good wear resistance and can handle the molding demands of PET preform production.

H13 Steel (1.2344): H13 is a hot work tool steel known for its high heat resistance, toughness, and hardness. It maintains its properties at elevated temperatures, making it suitable for high-temperature injection molding processes. H13 steel is chosen for PET preform molds when dealing with high production volumes or high-speed molding.

S136 or 420 Stainless Steel: Stainless steels like S136 or 420 are corrosion-resistant and offer good surface finish properties. They can be suitable for PET preform molds that require excellent surface finishing, especially for clear or transparent PET containers where appearance is critical.

These steel types are often preferred for PET preform molds due to their combination of hardness, wear resistance, machinability, and thermal properties necessary for the demanding conditions of injection molding. The specific choice among these steels depends on the requirements of the molding process, including factors like cooling rates, cycle times, production volumes, and surface finish requirements.

It's essential to consult with mold designers, engineers, or manufacturers experienced in PET preform molding to determine the most suitable steel type based on the specific needs and conditions of the intended molding process.