Bohler-Uddeholm,BÖHLER M303 EXTRA Plastic Mold Steel Tube,Pipe

Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Tube Product Information -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Tube Synonyms -:- For detailed product information, please contact sales. -:

Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Product Information -:- For detailed product information, please contact sales. -: # **Böhler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel** ## **Product Overview** **BÖHLER M303 EXTRA** is a premium **pre-hardened, corrosion-resistant chromium-nickel-molybdenum alloyed plastic mold steel** engineered for demanding molding applications requiring exceptional surface quality, good corrosion resistance, and consistent machinability. Supplied at a uniform hardness in the pre-hardened condition, this steel combines the operational convenience of ready-to-machine material with the enhanced performance characteristics of a modified martensitic stainless steel. The "EXTRA" designation signifies superior internal cleanliness and homogeneity achieved through advanced melting and processing techniques, making it particularly suitable for high-gloss surfaces and molds exposed to corrosive processing environments. --- ## **1. Key Characteristics & Advantages** * **Good Corrosion Resistance:** Offers improved resistance to rust, oxidation, and corrosive plastic decomposition byproducts compared to standard P20-type steels, extending mold life and reducing maintenance. * **Excellent Polishability:** Capable of achieving high-quality surface finishes (up to SPI A-2/B-1 level), suitable for many consumer product and technical component applications. * **Superior Machinability in Pre-Hardened State:** Provides excellent cutting performance at its delivery hardness, significantly reducing machining time and tool wear compared to higher-hardness steels. * **High Dimensional Stability:** Minimal internal stress and uniform properties ensure stable machining behavior and reduced risk of distortion during and after processing. * **Good Weldability:** Exhibits favorable characteristics for repair welding and modification using appropriate procedures and filler materials. * **Consistent & Homogeneous Properties:** The "EXTRA" quality ensures uniform hardness, microstructure, and mechanical behavior throughout the entire cross-section of the material. * **Good Wear Resistance:** For its hardness class, offers adequate resistance to abrasion from standard and moderately filled engineering plastics. --- ## **2. Typical Chemical Composition (Weight %)** | Element | Carbon (C) | Chromium (Cr) | Nickel (Ni) | Molybdenum (Mo) | Manganese (Mn) | | :--- | :---: | :---: | :---: | :---: | :---: | | **Content** | **0.20 - 0.25** | **~1.0** | **~1.0** | **~0.2** | **~1.5** | **Note:** This represents a typical modified P20+Ni+Cr composition. The exact, proprietary chemistry of M303 EXTRA is optimized by Böhler-Uddeholm for balanced performance. **Key Alloying Effects:** * **Chromium & Nickel:** The combined addition (typically ~1% each) enhances hardenability, improves toughness, and contributes to the material's enhanced corrosion resistance compared to standard low-alloy P20. * **Molybdenum:** Increases strength and hardenability. * **Controlled Carbon Content:** Balances machinability with sufficient as-supplied strength. * **"EXTRA" Manufacturing:** Implies strict control over impurity elements (S, P) and non-metallic inclusions, leading to better polishability and more predictable machining. --- ## **3. Physical & Mechanical Properties** ### **Physical Properties (at ~31 HRC):** * **Density:** ~7.85 g/cm³ * **Thermal Conductivity:** ~36 W/(m·K) at 20°C * **Modulus of Elasticity:** ~205 GPa * **Coefficient of Thermal Expansion:** ~12.5 x 10⁻⁶/K (20-100°C) ### **Mechanical Properties (Delivery Condition):** * **Hardness:** **290 - 330 HBW (30 - 34 HRC)** * **Tensile Strength:** ~1000 - 1100 MPa * **Yield Strength (0.2% offset):** ~850 - 950 MPa * **Elongation at Break:** ~12-15% * **Impact Toughness (Charpy V):** Typically > 40 J * **Machinability:** Very good for its hardness; superior to many other pre-hardened steels of similar alloy content. --- ## **4. Primary Applications** BÖHLER M303 EXTRA is a versatile, high-quality pre-hardened steel suitable for a wide range of plastic injection molds: * **High-Gloss Surface Molds:** Automotive interior trim, consumer electronics housings, appliance parts. * **Technical Component Molds:** For engineering plastics (PA, PBT, PC, ABS) where good surface finish and dimensional stability are required. * **Molds for Slightly Corrosive Environments:** Applications involving moist operating conditions or plastics that release mild acidic byproducts (e.g., certain PVC blends, flame-retardant grades). * **Large Mold Bases and Plates:** Where consistent machinability and stability in large sections are critical. * **Insert Applications:** For cores and cavities in multi-cavity molds where corrosion resistance can help prevent issues during downtime. * **General-Purpose High-Quality Molds:** Where the reliability and consistency of a premium pre-hardened steel are valued over standard grades. --- ## **5. Relevant International Standards & Comparable Grades** M303 EXTRA is a proprietary Böhler-Uddeholm grade. Its composition and performance position it within the family of modified, pre-hardened P20+Ni-type steels. | Standard | Grade / Designation | Country/Region | Similarity / Key Difference | | :--- | :--- | :--- | :--- | | **Proprietary (Böhler-Uddeholm)** | **M303 EXTRA** | International | The reference premium modified P20+Ni grade with enhanced consistency. | | **AISI / ASTM** | **P20+Ni Modified** | USA | M303 EXTRA fits this broad category, representing a high-quality variant. | | **DIN / Werkstoff** | **1.2738 (≈35CrNiMo6)** | Germany/EU | The standard pre-hardened mold steel with Nickel. M303 EXTRA is a premium version with guaranteed "EXTRA" properties. | | **JIS** | **PX5** | Japan | A Japanese pre-hardened Ni-containing mold steel. Similar application target. | | **Other Proprietary** | **IMPAX® SUPREME (P20+Ni)** | Uddeholm | A similar premium pre-hardened Ni-alloyed grade within the same supplier's portfolio. M303 EXTRA may represent a specific quality tier or variant. | **Important:** Specifying **"M303 EXTRA"** ensures receipt of Böhler-Uddeholm's premium-grade material with guaranteed machinability, polishability, and homogeneity. --- ## **6. Processing & Fabrication Guidelines** * **Machining:** **Excellent machinability** in its supplied state. Use sharp carbide tools for optimal results. Its consistent hardness and structure provide predictable tool life and good surface finish from machining. * **Drilling & Tapping:** Performs very well. Standard practices and coolants apply. * **Grinding:** Straightforward process. Use aluminum oxide wheels with standard parameters. * **EDM (Sinker & Wire):** Suitable and performs well. For critical surface areas that will be polished, a light tempering/stress relief at 400-450°C after EDM can help improve polishability by relieving the transformed surface layer. * **Polishing:** Good polishability. Can be polished to a high gloss using standard abrasive and diamond compound sequences. The homogeneous "EXTRA" structure minimizes the risk of pulling out inclusions. * **Welding:** Good weldability for repair and modification. * **Pre-heat:** 200 - 250°C is typically sufficient. * **Filler Metal:** Use a soft, crack-resistant filler (e.g., AWS ER70S-6 or a proprietary P20-type welding wire). * **Post-Weld:** Temper immediately at 400 - 450°C, then slow cool to relieve stresses. * **Surface Treatment:** Can be nitrided (gas or plasma) to increase surface hardness significantly (up to ~700 HV) for improved wear resistance on specific areas like gates or runners, though this is often not necessary for its primary applications. --- ## **7. Conclusion** **BÖHLER M303 EXTRA** is a **high-reliability, premium pre-hardened mold steel** that offers a practical upgrade over standard P20 materials. By incorporating nickel and chromium for enhanced properties and guaranteeing superior internal quality through its "EXTRA" manufacturing, it provides mold makers with a material that delivers consistent performance, easier machining, and better surface finish capabilities. It is an ideal choice for a wide spectrum of plastic injection molds where the combination of **ready-to-use convenience, good corrosion resistance, and reliable polishability** is required. For applications that demand more than basic P20 but do not require the extreme polishability of optical grades (like M238/M261) or the full corrosion resistance of stainless steels (like STAVAX), M303 EXTRA represents a cost-effective and high-performance solution that balances quality, productivity, and mold longevity. -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Specification Dimensions Size： Diameter 20-1000 mm Length <6891 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Properties -:- For detailed product information, please contact sales. -:

Applications of Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Tube -:- For detailed product information, please contact sales. -: Chemical Identifiers Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Tube -:- For detailed product information, please contact sales. -:

Packing of Bohler-Uddeholm BÖHLER M303 EXTRA Plastic Mold Steel Tube -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Tube drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3362 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition