International Mold Steel Wire NAK55 Precipitation Hardened Mold Steel Wire

International Mold Steel Wire NAK55 Precipitation Hardened Mold Steel Wire Product Information -:- For detailed product information, please contact sales. -: International Mold Steel Wire NAK55 Precipitation Hardened Mold Steel Wire Synonyms -:- For detailed product information, please contact sales. -:

International Mold Steel NAK55 Precipitation Hardened Mold Steel Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: International Mold Steel NAK55 Precipitation Hardened Mold Steel** International Mold Steel (IMS) NAK55 is a premium, nickel-aluminum (Ni-Al) precipitation hardening mold steel supplied in a solution-treated and pre-aged condition. It is renowned for its **exceptional combination of high hardness (40-43 HRC) in the as-supplied state, outstanding machinability, superior polishability, and excellent dimensional stability**. Unlike conventional quenched and tempered steels, NAK55 achieves its hardness through a dispersion of fine intermetallic compounds (Ni₃Al) formed during a controlled aging process, which occurs without the phase transformation and associated distortion of martensitic hardening. This steel is specifically engineered for the production of **high-precision, long-run plastic injection molds and die-casting molds** requiring superior surface finishes and minimal post-machining distortion. Its unique metallurgy allows it to be machined, polished, and textured in its hard state, streamlining the mold-making process and reducing the risks associated with heat treatment. NAK55 is a cornerstone material in industries demanding the highest levels of surface quality and dimensional accuracy, such as optical components, consumer electronics, and automotive interiors. --- ## **1. Chemical Composition (Weight %)** The composition is a nickel-aluminum alloy system with added sulfur for machinability and chromium for hardenability/corrosion resistance. | **Element** | **Nickel (Ni)** | **Aluminum (Al)** | **Chromium (Cr)** | **Molybdenum (Mo)** | **Copper (Cu)** | **Sulfur (S)** | | :--- | :--- | :--- | :--- | :--- | :--- | :--- | | **Content** | **2.80 - 3.50** | **1.00 - 1.50** | **0.80 - 1.30** | **0.20 - 0.50** | **0.80 - 1.30** | **0.05 - 0.12** | | **Role** | **Primary hardening element.** Forms the hardening precipitate Ni₃Al (gamma prime phase) with Aluminum during aging, providing strength and hardness without martensitic transformation. | Partners with Nickel to form the age-hardening Ni₃Al precipitates. | Enhances hardenability of the matrix during solution treatment and provides mild corrosion resistance. | Increases strength and refines the grain structure. | Contributes to age hardening and improves corrosion resistance. | Forms manganese sulfide (MnS) inclusions that act as chip breakers, granting **exceptional free-machining characteristics** in the hardened state. | *Note: Iron (Fe) constitutes the remainder. Manganese (Mn) is present to balance the sulfur. This is a low-carbon, precipitation-hardening alloy steel.* --- ## **2. Physical & Mechanical Properties** *Supplied in a solution-treated and pre-aged condition with a uniform hardness of 40-43 HRC.* * **Density:** ~7.8 g/cm³ * **Modulus of Elasticity:** ~190-200 GPa (slightly lower than tool steels due to microstructure) * **Thermal Conductivity:** Moderate. * **As-Supplied Hardness:** **40 - 43 HRC.** This pre-hardened state allows for direct machining of complex geometries without subsequent heat treatment. * **Machinability:** **Exceptional.** One of its most celebrated features. It machines with ease, producing short, broken chips and yielding excellent surface finishes even at high hardness, dramatically reducing tool wear and machining time. * **Polishability:** **Superb.** Capable of achieving ultra-high mirror finishes (e.g., SPI-A1, #12000+ grit) due to its fine, uniform, and non-directional microstructure free of hard carbides. Ideal for optical and high-gloss parts. * **Photographic Etchability (Texturing):** **Excellent.** Produces sharp, consistent textures with high definition. * **Dimensional Stability:** **Excellent.** No phase change occurs during final aging or in service under typical molding temperatures (<300°C/570°F), ensuring minimal movement after machining. * **Toughness & Wear Resistance:** **Good.** Adequate for most plastic injection molding applications. For molding highly abrasive filled materials (e.g., glass fiber), nitriding can be applied to enhance surface wear resistance. * **Weldability:** Fair to good with proper procedure (pre-heat, specific electrodes). Weld repairs are common. --- ## **3. Processing & Thermal Treatment** NAK55 follows a specific thermal cycle set by the mill; the mold maker primarily performs machining and finishing. 1. **Mill Processing:** The steel undergoes **Solution Treatment** (heated to dissolve alloying elements) followed by quenching and a **Pre-Aging** process. It is supplied in this hardened (40-43 HRC), stabilized condition. 2. **Machining (User):** The mold maker machines the steel directly in its hard state. No customer annealing or hardening is required or possible. 3. **Aging (Optional - User):** After machining, a low-temperature **Aging Treatment** (450-500°C / 840-930°F for several hours) may be performed to relieve machining stresses and slightly increase hardness (by 1-2 HRC). This is often done for high-precision molds. 4. **Finishing:** Excellent response to polishing, texturing, and coating (e.g., Ni-P plating, DLC). 5. **Nitriding:** Commonly applied to increase surface hardness to 65-70 HV for improved wear and anti-sticking properties. --- ## **4. Key Applications** NAK55 is the material of choice for high-end, precision plastic injection molds requiring flawless surfaces and stability. * **Optical Molds:** For lenses, light guides, reflectors, and display components. * **High-Gloss & Appearance Parts Molds:** For automotive interiors (dashboards, trim), consumer electronics (housings, bezels), and appliances. * **Molds for Engineering Plastics:** Including ABS, PC, PC/ABS, POM, and nylon (unfilled or mildly filled). * **Die-Casting Molds for Zinc & Magnesium** (for lower melting point alloys). * **Large, Complex Cavity & Core Inserts** where machining in a pre-hardened state reduces risk. --- ## **5. International Standards & Cross-References** NAK55 is a Japanese-origin, proprietary grade that has become an industry benchmark. It is part of the "NAK" series of precipitation-hardening mold steels. * **JIS:** No official JIS designation. It is a proprietary trade name. * **AISI/SAE:** No direct equivalent. Functionally similar in application to pre-hardened mold steels like P20, but with a different hardening mechanism and superior polishability. * **European (EN):** No direct equivalent. The closest in concept are special Ni-Al age-hardening steels. * **Common Trade Names/Equivalents:** * **Daido NAK55** (the original manufacturer's grade). * **Hitachi HPM75** (similar Ni-Al age-hardening steel). * **Uddeholm Unimax** (Different chemistry, but similar pre-hardened, high-polish application). * **Böhler M333 (Isodur 333)**. --- ## **6. Advantages & Limitations** **Advantages:** * **Machinability in Hard State:** Unmatched ease of machining at 40+ HRC, saving time and cost. * **Superb Polishability & Texture Reproduction:** Delivers the highest surface quality. * **Dimensional Stability:** Eliminates risks of distortion from post-machining heat treatment. * **Good Overall Performance:** Balanced hardness, toughness, and wear resistance for most molding needs. * **Proven Track Record:** An industry standard for high-quality molds for decades. **Limitations:** * **Lower Maximum Hardness:** Not suitable for applications requiring core hardness above ~43 HRC. * **Moderate Wear Resistance vs. Tool Steels:** Requires nitriding for highly abrasive plastics. * **Not a Hot Work Steel:** Limited to lower-temperature molding applications. * **Higher Cost:** More expensive than standard pre-hardened steels like P20. * **Limited Weldability:** Requires expertise for successful repairs. --- ## **7. Summary** **International Mold Steel NAK55 is the definitive high-performance, pre-hardened mold steel for applications where surface perfection, dimensional accuracy, and machining efficiency are non-negotiable.** Its unique precipitation-hardening metallurgy provides a "best of both worlds" scenario: the hardness needed for production longevity and the workability of a much softer steel. By enabling complex molds to be machined to a mirror finish directly from a hardened block, NAK55 reduces lead times, mitigates manufacturing risks, and ensures the highest possible quality for molded plastic parts. It remains the gold standard for mold makers serving the optical, automotive, and high-end consumer goods industries. -:- For detailed product information, please contact sales. -: International Mold Steel NAK55 Precipitation Hardened Mold Steel Specification Dimensions Size： Diameter 20-1000 mm Length <7004 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. -: International Mold Steel NAK55 Precipitation Hardened Mold Steel Properties -:- For detailed product information, please contact sales. -:

Applications of International Mold Steel Wire NAK55 Precipitation Hardened Mold Steel Wire -:- For detailed product information, please contact sales. -: Chemical Identifiers International Mold Steel Wire NAK55 Precipitation Hardened Mold Steel Wire -:- For detailed product information, please contact sales. -:

Packing of International Mold Steel Wire NAK55 Precipitation Hardened Mold Steel Wire -:- 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 3475 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