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Which type of steel is suitable for cold extrusion molds?

Cold extrusion is a near-net-shape forming process, in which metal blanks undergo plastic deformation inside the die cavity under room temperature. It is widely applied in mass production of fasteners, motor rotors, automotive connectors, battery casings and other components. Under working conditions, the dies bear ultra-high contact compressive stress up to thousands of megapascals, severe friction from flowing metal, and fatigue loads caused by repeated impacts. Premature chipping or wear will directly affect the dimensional accuracy of finished parts and production delivery schedule. Therefore, selecting the right mold steel together with proper heat treatment are two core factors determining the service life of cold extrusion dies. 1. Core Performance Requirements for Cold Extrusion Die Materials Under cold extrusion working conditions, mold steel must satisfy four key properties simultaneously: High hardness and compressive strength to resist cavity collapse and minor plastic deformation; Excellent wear resistance to maintain dimensional accuracy after long-term production; Sufficient toughness: hard surface with tough core to prevent chipping and spalling; High multi-impact fatigue resistance to adapt to cyclic loads of dozens of strokes per minute. Material selection is essentially balancing hardness and toughness. Excessively high hardness tends to cause die chipping, while overemphasizing toughness will lead to rapid wear. 2. Common Cold Extrusion Mold Steels and Application Scenarios Category Representative Grades Features Typical Applications High-carbon high-chromium ledeburitic steel Cr12、Cr12MoV(≈D2) Good wear resistance, low quenching deformation, medium toughness Cold extrusion punches and dies for simple-shaped parts in small and medium batches Medium-alloy cold work steel Cr5Mo1V(≈A2)、7CrSiMnMoV Air-hardening, better strength & toughness than Cr12MoV Medium & large dies with complex cavities prone to cracking Low-alloy tool steel 9SiCr、CrWMn Low cost, good machinability Low-load, small-batch extrusion of aluminum and mild steel parts High-speed steel W6Mo5Cr4V2(≈M2)、W18Cr4V High hot hardness and compressive strength Cold extrusion of high-strength steel and stainless steel for medium and large batches Reduced-carbon high-toughness HSS 6W6Mo5Cr4V(6W6) Wear resistance close to M2 with greatly improved toughness Applications with heavy impact load and frequent die chipping New high-strength & toughness cold work steel LD(7Cr7Mo2V2Si)、65Nb、LM2、GD Balanced wear resistance and toughness; service life several times longer than Cr12MoV Punches and dies for high-demand special-shaped parts such as engine components and lock cores Premium materials Powder metallurgy HSS, steel-bonded cemented carbide, cemented carbide Extremely long service life, high material cost Large-volume long-run production where high die cost can be amortized 3. Material Selection Guide: Match Grades by Production Batch and Load Small batch, trial production, aluminum / mild steel soft materials:Conventional cold work steel such as Cr12MoV and 9SiCr are sufficient with minimum die manufacturing cost. Medium batch, carbon steel or low-alloy structural steel:Prioritize high-toughness grades including 6W6, LD and 65Nb. Slightly higher material cost brings multiple times longer service life for optimal overall economy. Mass production, high-strength steel / stainless steel extrusion:Adopt high-speed steel (M2) or powder metallurgy HSS, paired with cemented carbide die inserts to avoid frequent die repair and production downtime. Complex cavity, uneven wall thickness and high cracking risk:Avoid high-carbon high-chromium steel. Choose air-quenched low-distortion grades like 7CrSiMnMoV and A2 to solve cracking issues first before optimizing wear resistance. 4. Premium Steel Requires Proper Heat Treatment & Surface Treatment For the same mold steel, different heat treatment processes can result in several-fold differences in die service life: Quenching and tempering:Cold extrusion dies are normally hardened to HRC60–64. For punches under heavy impact, hardness shall be reduced appropriately to improve toughness. Surface strengthening:TD treatment, PVD coating (TiN/TiAlN), gas soft nitriding or hard chrome plating can further enhance surface wear resistance, delivering prominent benefits for stainless steel and superalloy extrusion. Toughening treatment:Low-temperature quenching and multiple tempering for M2 and 6W6 high-speed steel can greatly boost toughness with almost no hardness loss. Conclusion There is no universal best mold steel for cold extrusion dies. The optimal choice depends on production volume, workpiece material hardness and die structure. This is the mature selection principle widely verified in the industry.

2026-03-10
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Which type of steel is suitable for cold extrusion molds?

The 15th Five-Year Plan: How China’s Manufacturing Strives for Leadership

Advanced manufacturing is an important pillar of the real economy. “…During the 15th Five-Year Plan period, we will accelerate the development of advanced manufacturing,” “accelerate the building of a modern industrial system with advanced manufacturing as the backbone,” and “strive to enhance advanced manufacturing capabilities.” On August 26, at the series of themed press conferences on “Getting Off to a Good Start for the 15th Five-Year Plan” held by the State Council Information Office, “advanced manufacturing” became a high-frequency term, sending a clear and powerful signal. On August 24, at the second World Humanoid Robot Games, a robot from the Beijing Humanoid · Huake team competed in the weightlifting (heavyweight) event. Photo by Xinhua reporter Ju Huangzong The “leadership” of advanced manufacturing is rooted in the fertile soil of industrial structure optimization. “We will focus on optimizing the industrial structure, making coordinated progress in upgrading and renovating traditional industries, nurturing and strengthening emerging industries, and making forward-looking arrangements for future industries, while maintaining and developing a complete industrial system,” said Xin Guobin, Vice Minister of Industry and Information Technology. Promoting the “renovation” of traditional industries: deepening pilot programs for the new-type technological transformation of manufacturing in cities, strengthening technological innovation, equipment renewal and model innovation, and advancing the intelligent, green and integrated development of traditional industries. Accelerating the “lead” of emerging industries: speeding up the development of emerging pillar industries such as integrated circuits, aerospace, biomedicine, the low-altitude economy, new-type energy storage and intelligent robots. Supporting future industries to “take root”: promoting quantum technology, biomanufacturing, hydrogen energy and nuclear fusion energy, brain-computer interfaces, embodied intelligence and the sixth-generation mobile communications (6G) to become new economic growth points… The continuous optimization of the industrial structure is building a solid foundation and accumulating momentum for advanced manufacturing. The “leadership” of advanced manufacturing is grounded in breakthroughs in core technologies. A detail at the press conference was striking: foldable-screen phones can be folded repeatedly, thanks to domestically produced ultra-thin flexible glass that has achieved 30micrometer mass production — a thickness only about one-quarter of that of a sheet of A4 paper. The cycle of “one generation of materials, one generation of equipment, one generation of industries” reflects the deep integration of scientific and technological innovation with industrial innovation. Strengthening original innovation and tackling key core technologies, building and making good use of platforms such as national manufacturing innovation centers and manufacturing pilot-test platforms, and channeling innovation resources toward enterprises… A series of measures at the press conference will promote the seamless connection between the innovation chain and the industrial chain, continuously enhancing the overall effectiveness of the manufacturing innovation system. A new-energy vehicle about to roll off the assembly line at the terminal assembly workshop of the Seres Super Factory (Fenghuang) in Shapingba District, Chongqing. Photo by Xinhua reporter Wang Quanchao The “leadership” of advanced manufacturing ultimately must translate into a leap in manufacturing capabilities. Output of new-energy vehicles, power batteries and key materials accounts for more than 70% of the global total; the annual output of industrial robots has risen to 773,000 units… These “business cards” of Made in China mark the solid confidence underpinning advanced manufacturing capabilities. At the press conference, a package of measures was dedicated to boosting manufacturing capabilities — Integration will deepen further: advancing the “AI + Manufacturing” special initiative; promoting the large-scale application of 5G, the industrial internet and other technologies in manufacturing and other fields; promoting the deep integration of advanced manufacturing with modern service industries, and accelerating the cultivation of new models and new business forms such as platform-based design and customized production. The green and low-carbon pathway will become clearer: making coordinated efforts to optimize the industrial and energy consumption structures, accelerating electrification transformation and the application of green energy, and implementing a digital identity card management system for power batteries. It is reported that during the 15th Five-Year Plan period, 500 zero-carbon factories will be cultivated and built; by 2030, the comprehensive utilization of used power batteries will strive to reach more than one million tons per year. The “leadership” of advanced manufacturing relies on a sound industrial ecosystem. “We should be the ‘family member’ of enterprises, implement the key tasks of deepening reform, strengthen planning guidance, standards and norms, and policy support, deepen highlevel opening-up and cooperation, and foster a sound industrial ecosystem,” said Xin Guobin. The Plan for Promoting the Development of Small and Medium-sized Enterprises during the 15th Five-Year Plan period will be officially released soon, making systematic arrangements around cultivating high-quality enterprises, deepening digital and intelligent empowerment, and strengthening the supply of production factors, so as to promote the highquality development of SMEs. In addition, the Ministry of Industry and Information Technology will focus on improving industrial governance capabilities, improving the legal and regulatory system, and improving the capacity monitoring and early-warning mechanism, while strengthening planning guidance, capacity regulation, price governance and industry self-discipline, comprehensively rectifying “involution-style” competition, and building a market-oriented, law-based and internationalized business environment. The goals are clear and the path is set. Chinese manufacturing is racing into the new fiveyear period with a posture of striving for “leadership.” Source: Xinhua News Agency

2026-03-10
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How to Distinguish and Select Cold-work, Hot-work & Plastic Mold Steel

For metal forming and plastic injection industries, molds are the core carrier for product shaping, while mold steel serves as the “backbone” of molds. When facing mold wear and short service life, many manufacturers only focus on machining processes and ignore proper steel grade matching. Foshan Jinjun Metal (Taiyuan Mold Steel) compiles professional knowledge to clarify categories, characteristics and application ranges of three mainstream mold steel families. 1. Cold-work Mold Steel: Wear-resistant Material for Room-temperature Forming Cold-work mold steel bears heavy pressure, friction and impact at ambient temperature. It requires high wear resistance and sufficient toughness to avoid edge chipping, abrasion and collapse. Applications: Cold extrusion, stamping, blanking, cold forming rolls, cutting dies, forming rollers for keel machines and rack machines. Common grades: Cr12MoV, DC53, SKD11, LD, 6W6, powder high-speed steel. Typical failures: Edge wear, chipping and cracking. 2. Hot-work Mold Steel: High-temperature Steel with Thermal Fatigue Resistance Hot-work mold steel works under repeated heating and cooling cycles. It features excellent high-temperature strength and thermal fatigue resistance to prevent thermal cracks and softening. Applications: Aluminum alloy die casting, hot forging and hot extrusion dies. Common grades: H13 (2344ESR). Typical failures: Thermal fatigue cracking, high-temperature softening and cavity collapse. 3. Plastic Mold Steel: Optimized for Polishing & Machinability Plastic mold steel is not subjected to heavy impact. Its key advantages are good machinability, mirror polishing performance and corrosion resistance. Many grades are delivered in pre-hardened condition for direct machining. Applications: Injection molds for home appliance housings, automotive interior parts and daily consumer goods. Common grades: S136, 718, 2311, 2738. Typical failures: Failed mirror finish, plastic corrosion and surface scratches. Tip: Longer mold service life does not simply come from higher hardness. Higher hardness usually reduces toughness. Excessively high hardness selected blindly will easily cause mold cracking. Material selection should consider load, production volume and workpiece material, matched with proper heat treatment to maximize mold lifespan. Jinjun Metal supplies mold steel and complete cold roll-forming lines. With abundant on-site service experience, we provide free material selection consultation and heat-treatment recommendations to solve your mold material challenges in one stop. Technical teams from manufacturing enterprises are welcome to contact us for discussion.

2026-10-20
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