Latrobe,LSS™ 420 MQ Plastic Mold Steel Wire (AISI 420)

Latrobe LSS™ 420 MQ Plastic Mold Steel Wire (AISI 420) Product Information -:- For detailed product information, please contact sales. -: Latrobe LSS™ 420 MQ Plastic Mold Steel Wire (AISI 420) Synonyms -:- For detailed product information, please contact sales. -:

Latrobe LSS™ 420 MQ Plastic Mold Steel (AISI 420) Product Information -:- For detailed product information, please contact sales. -: ### **Product Introduction: Latrobe LSS™ 420 MQ Premium Plastic Mold Steel** **Overview** Latrobe LSS™ 420 MQ (Mirror Quality) is a high-purity, martensitic stainless mold steel specifically engineered for the demanding requirements of plastic injection molding and other precision tooling applications. Based on the AISI 420 standard, this grade undergoes advanced melting and processing to achieve exceptional cleanliness, uniform microstructure, and superior polishability. The "MQ" designation signifies its premium quality, optimized for mirror-like surface finishes, excellent corrosion resistance, and good machinability in the pre-hardened state. It is the material of choice for molding a wide range of plastics, especially those requiring optical clarity, high-gloss finishes, or those that are corrosive (e.g., PVC, flame-retardant materials). **Key Advantages** * **Superior Corrosion Resistance:** Provides excellent resistance to rust and chemical attack from moisture, acids released by certain plastics (e.g., PVC), and common mold coolants, minimizing downtime for maintenance. * **Exceptional Polishability:** The high-purity, fine-grained, and homogeneous structure allows it to be polished to a true **#1 Diamond (A1) mirror finish** (Ra < 0.012 μm), which is critical for molding optical lenses, cosmetic parts, and high-gloss consumer products. * **Excellent Etchability:** Responds consistently and uniformly to photochemical etching (PEM) for creating textured surfaces (e.g., leather grain, geometric patterns) on molded parts. * **Good Machinability & EDM Performance:** Offers better machinability and electrical discharge machining (EDM) characteristics than higher-carbon stainless tool steels, reducing lead times and tooling costs in the pre-hardened state. * **Pre-Hardened & Dimensionally Stable:** Supplied in a through-hardened and tempered condition, ready for machining. It exhibits minimal size change during final heat treatment (if required), ensuring dimensional accuracy of the finished mold. **International Standards & Specifications** * **AISI / SAE:** 420 (Modified) * **ASTM:** A581 (Standard Specification for Free-Machining Stainless Steel Wire and Wire Rods - not a direct mold steel spec, but defines composition) * **UNS:** S42000 * **DIN / EN:** 1.2083 / X33CrS16 (A common European equivalent for plastic mold steels) * **JIS:** SUS420J2 * **Common Trade Names:** "420 Stainless Mold Steel," "Polmax," "Stavax ESR" (similar premium grades from other manufacturers). **Chemical Composition (Typical Weight %)** The composition is balanced to provide corrosion resistance through chromium, while maintaining good hardness, polishability, and avoiding excessive carbon which can harm toughness and polishability. | Element | Carbon (C) | Chromium (Cr) | Silicon (Si) | Manganese (Mn) | Sulfur (S) | | :--- | :---: | :---: | :---: | :---: | :---: | | **% Range** | 0.33 - 0.43 | 12.00 - 14.00 | ≤ 1.00 | ≤ 1.00 | ≤ 0.030 (Low) | *Note: May contain controlled amounts of other elements like Nickel (Ni) and Vanadium (V) for enhanced properties.* **Physical & Mechanical Properties (Pre-Hardened Condition)** Latrobe LSS™ 420 MQ is typically supplied and used in a pre-hardened and tempered condition, ready for machining. * **Hardness (Supplied):** **30 - 34 HRC** (approx. 285 - 330 HB). This range provides an optimal balance of machinability, polishability, and wear resistance for most plastic molding applications. * **Hardness (After Final Hardening):** If through-hardening is performed, it can achieve a maximum hardness of approximately **50 - 54 HRC**. * **Tensile Strength:** ~1000 - 1200 MPa (145 - 175 ksi) in the pre-hardened state. * **Yield Strength (0.2% Offset):** ~800 - 950 MPa (116 - 138 ksi) in the pre-hardened state. * **Thermal Conductivity:** ~25 W/m·K (at 20°C) – Lower than non-stainless mold steels, which should be considered in cooling channel design. * **Coefficient of Thermal Expansion:** ~10.5 x 10⁻⁶ /K (20-100°C). **Typical Product Applications** Latrobe LSS™ 420 MQ is the industry standard for a vast range of plastic injection molds and tooling. 1. **High-Gloss & Optical Molds:** * **Lenses:** Automotive lights, optical instruments, eyeglasses. * **Consumer Electronics:** Housings for phones, tablets, TVs, and appliances requiring a flawless surface finish. * **Cosmetic Packaging:** Containers for creams, lotions, and makeup. 2. **Corrosive Plastic Molds:** * **PVC Fittings & Components:** For plumbing, windows, and profiles. * **Flame-Retardant (FR) Plastics:** Electronics housings and components. * **Polyurethane (PU) Foam Molds:** For automotive interiors and insulation panels. 3. **General Precision Mold Components:** * **Mold Cavities & Cores:** For engineering plastics (POM, PA, PC, ABS). * **Ejector Sleeves, Guide Pins/Bushes:** Where corrosion resistance prevents seizing. * **Hot Runner Manifolds & Nozzles:** In systems processing corrosive materials. **Processing & Heat Treatment Notes** * **Machining:** Can be machined using standard high-speed steel (HSS) or carbide tools. Carbide is recommended for longer tool life, especially in the pre-hardened state. * **Heat Treatment (Optional):** For maximum corrosion and wear resistance, it can be hardened by heating to 980-1050°C (1800-1920°F), oil or air quenching, and tempering in the range of 200-400°C (390-750°F) to the desired hardness (typically 48-52 HRC). Stress relieving after rough machining is advised. * **Polishing:** Follow a progressive sequence from coarse to fine diamond compound. The homogeneous structure ensures a pit-free, high-quality finish. **Conclusion** Latrobe LSS™ 420 MQ represents the benchmark for corrosion-resistant, high-polish plastic mold steels. Its reliable performance in the pre-hardened state, combined with its ability to achieve flawless surface finishes and resist aggressive molding environments, makes it an indispensable material for mold builders worldwide. For applications demanding both aesthetic perfection and longevity in corrosive service, 420 MQ delivers proven value and performance. -:- For detailed product information, please contact sales. -: Latrobe LSS™ 420 MQ Plastic Mold Steel (AISI 420) Specification Dimensions Size： Diameter 20-1000 mm Length <7214 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. -: Latrobe LSS™ 420 MQ Plastic Mold Steel (AISI 420) Properties -:- For detailed product information, please contact sales. -:

Applications of Latrobe LSS™ 420 MQ Plastic Mold Steel Wire (AISI 420) -:- For detailed product information, please contact sales. -: Chemical Identifiers Latrobe LSS™ 420 MQ Plastic Mold Steel Wire (AISI 420) -:- For detailed product information, please contact sales. -:

Packing of Latrobe LSS™ 420 MQ Plastic Mold Steel Wire (AISI 420) -:- 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 Wire 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 3685 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