Plastic Mould Steels

The requirements for mould steels are more diverse than in any other manufacturing process. Wear resistance, especially when processing fibre-reinforced plastics, and in addition corrosion resistance, machinability, polishability, thermal conductivity and mechanical properties are among the most important criteria.

The plastics processing industry asks for a comprehensive portfolio of tool steels and high‑performance remelted or powder‑metallurgical tooling materials. These materials are used in demanding applications such as injection moulding, blow moulding and plastic extrusion, where tool steels must combine wear resistance, corrosion resistance, toughness, thermal stability and excellent polishability. With the industry’s most versatile program of stainless mould steels, BÖHLER and Uddeholm are regarded as market leaders for tool steels for plastic processing and the materials ensure: high tool life, • precise processing,stable cooling performance,flawless surface quality on plastic components. Tailored steel grades meet specific challenges such as high temperatures (up to ~400 °C), aggressive plastics (e.g., PVC), fibre‑reinforced materials (GRP), and large tool dimensions. Through decades of metallurgical expertise, Uddeholm’s Stainless Concept and BÖHLER’s advanced ESR and PM steels deliver optimised combinations of corrosion resistance, wear resistance, polishability and toughness, enabling reliable production of high‑volume, high‑quality plastic parts. The correct steel selection—combined with value‑adding services like heat treatment, PVD coatings and additive manufacturing—ensures superior tool performance and reduced cost per part. BÖHLER and Uddeholm tool steels are developed and manufactured in dedicated facilities in Kapfenberg (Austria) and Hagfors (Sweden), supporting tooling manufacturers worldwide with premium materials engineered for the most demanding mould applications.

Related Products

  • Uddeholm Corrax

    Uddeholm Corrax is a precipitation hardening steel with a unique set of properties that makes it perfect for many demanding applications. The superior resistance against corrosion combined with a hardness up to 50 HRC and a simple heat treatment makes Uddeholm Corrax the obvious choice for long run series of aggressive plastics such as PVC. The chemical composition makes Uddeholm Corrax easy to process by Additive Manufacturing. Hence, it is also available as powder for Laser Powder Bed Fusion (LPBF) and Laser Metal Deposition (LMD). Benefits Very good corrosion resistance Flexible hardness of 34-50 HRC achieved by ageing No hard “white layer” after EDM

    Uddeholm Corrax

    • Corrosion resistance 95%
    • Wear resistance 50%
    • Polishability 70%
    • Toughness 70%
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    • Plastic Mould

    Uddeholm Corrax is a precipitation hardening steel with a unique set of properties that makes it perfect for many demanding applications. The superior resistance against corrosion combined with a hardness up to 50 HRC and a simple heat treatment makes Uddeholm Corrax the obvious choice for long run series of aggressive plastics such as PVC. The chemical composition makes Uddeholm Corrax easy to process by Additive Manufacturing. Hence, it is also available as powder for Laser Powder Bed Fusion (LPBF) and Laser Metal Deposition (LMD). Benefits Very good corrosion resistance Flexible hardness of 34-50 HRC achieved by ageing No hard “white layer” after EDM

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  • Uddeholm Elmax SuperClean

    Uddeholm Elmax Super Clean is a powder metallurgically produced mould steel characterized by a combination of very good wear resistance, corrosion resistance and dimensional stability. Recommended for long production runs of smaller and complicated shapes and/or reinforced plastics. High wear resistance is normally connected to low corrosion resistance and vice versa. In Uddeholm Elmax SuperClean it has however been able to achieve this unique combination of properties by a powder-metallurgy-based production. Uddeholm Elmax SuperClean offers a possibility to make long-life, low maintenance moulds for the best overall moulding economy. Benefits Less wear because of god wear resistance Less indentations because of compressive strength Less maintenance because of corrosion resistance Less adjustments after heat treatment because of good dimensional stability Standard specification AFNOR Z170 CVD 17.3

    Uddeholm Elmax SuperClean

    • Corrosion resistance 60%
    • Wear resistance 90%
    • Polishability 80%
    • Toughness 40%
    Read More
    • Plastic Mould

    Uddeholm Elmax Super Clean is a powder metallurgically produced mould steel characterized by a combination of very good wear resistance, corrosion resistance and dimensional stability. Recommended for long production runs of smaller and complicated shapes and/or reinforced plastics. High wear resistance is normally connected to low corrosion resistance and vice versa. In Uddeholm Elmax SuperClean it has however been able to achieve this unique combination of properties by a powder-metallurgy-based production. Uddeholm Elmax SuperClean offers a possibility to make long-life, low maintenance moulds for the best overall moulding economy. Benefits Less wear because of god wear resistance Less indentations because of compressive strength Less maintenance because of corrosion resistance Less adjustments after heat treatment because of good dimensional stability Standard specification AFNOR Z170 CVD 17.3

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  • Uddeholm Idun

    Uddeholm Idun is the world’s first patented corrosion resistant tool holder steel. It is delivered in pre-hardened condition and provides the possibility to start machining the finished part directly. Uddeholm Idun shares the superior qualities that always accompany the members of the Uddeholm Tool Holder Concept – meeting your requirements on durability while still being good to machine. With Uddeholm Idun we offer you even more: a possibility to change the game. A corrosion resistant steel grade that is delivered in pre-hardened condition. Uddeholm Idun allows you to skip the long and costly process of hardening, surface treatment and the transportation in between that is normally required with standard materials. A safe and reliable fast forward button to your finished product. It shortens tool making lead time and improves tool holder durability. It is e.g. perfect for custom made tool holders. Benefits Corrosion resistant Big savings in time and money Environmentally friendly

    Uddeholm Idun

    • Corrosion resistance 70%
    • Wear resistance 55%
    • Polishability 80%
    • Toughness 55%
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    • Plastic Mould

    Uddeholm Idun is the world’s first patented corrosion resistant tool holder steel. It is delivered in pre-hardened condition and provides the possibility to start machining the finished part directly. Uddeholm Idun shares the superior qualities that always accompany the members of the Uddeholm Tool Holder Concept – meeting your requirements on durability while still being good to machine. With Uddeholm Idun we offer you even more: a possibility to change the game. A corrosion resistant steel grade that is delivered in pre-hardened condition. Uddeholm Idun allows you to skip the long and costly process of hardening, surface treatment and the transportation in between that is normally required with standard materials. A safe and reliable fast forward button to your finished product. It shortens tool making lead time and improves tool holder durability. It is e.g. perfect for custom made tool holders. Benefits Corrosion resistant Big savings in time and money Environmentally friendly

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  • Uddeholm Mirrax 40

    Uddeholm Mirrax 40 is a prehardened remelted stainless tool steel, supplied at 40 HRC. Uddeholm Mirrax 40 is produced using the electroslag remelting (ESR) process – an additional step in the steelmaking process that ensures very clean steel. Consequently, Uddeholm Mirrax 40 is capable of being polished to a very high surface finish. In addition, the combination of high hardness with high toughness results in a mould with good resistance to indentations and minimize the risk of unexpected failures, leading to a safer mould and a prolonged tool life. Benefits Lower production costs Fast tool making Excellent surface finish possible Less maintenance work Safe production

    Uddeholm Mirrax 40

    • Corrosion resistance 70%
    • Wear resistance 40%
    • Polishability 80%
    • Toughness 60%
    Read More
    • Plastic Mould

    Uddeholm Mirrax 40 is a prehardened remelted stainless tool steel, supplied at 40 HRC. Uddeholm Mirrax 40 is produced using the electroslag remelting (ESR) process – an additional step in the steelmaking process that ensures very clean steel. Consequently, Uddeholm Mirrax 40 is capable of being polished to a very high surface finish. In addition, the combination of high hardness with high toughness results in a mould with good resistance to indentations and minimize the risk of unexpected failures, leading to a safer mould and a prolonged tool life. Benefits Lower production costs Fast tool making Excellent surface finish possible Less maintenance work Safe production

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  • Uddeholm Mirrax ESR

    Uddeholm Mirrax ESR is a through hardening corrosion resistant steel with very good polishability. Mainly intended for medium to large cross sections. It has a unique combination of toughness, corrosion resistance and through hardening properties. Benefits Low mould maintenance costs: The surface of cavity impressions retain their original finish over extended running periods. Moulds stored or operated in humid conditions require less protection. Low production costs: Water cooling channels are less affected by corrosion Heat transfer characteristics, and therefore cooling efficiency, are constant throughout the mould life, ensuring consistent cycle times. Safe mould use because of good toughness also in big dimensions

    Uddeholm Mirrax ESR

    • Corrosion resistance 90%
    • Wear resistance 70%
    • Polishability 90%
    • Toughness 60%
    Read More
    • Plastic Mould

    Uddeholm Mirrax ESR is a through hardening corrosion resistant steel with very good polishability. Mainly intended for medium to large cross sections. It has a unique combination of toughness, corrosion resistance and through hardening properties. Benefits Low mould maintenance costs: The surface of cavity impressions retain their original finish over extended running periods. Moulds stored or operated in humid conditions require less protection. Low production costs: Water cooling channels are less affected by corrosion Heat transfer characteristics, and therefore cooling efficiency, are constant throughout the mould life, ensuring consistent cycle times. Safe mould use because of good toughness also in big dimensions

    Read More
  • Uddeholm Orvar Supreme

    Uddeholm Orvar Supreme can be regarded as an “all-round” steel used in several application areas. Except for hot work application areas the steel is also used in moulds for plastics and as a material in high stressed axles. The high degree of purity and the very fine structure shows improvement in dies and components where high mechanical and thermal stresses are involved. Uddeholm Orvar Supreme is produced using the Electro-Slag-Refining (ESR) technique. The ESR process gives Uddeholm Orvar Supreme a high level of homogeneity and cleanliness which results in a high performance hot work tool steel of the highest quality. Benefits Improved tooling performance Uddeholm Orvar Supreme meets the North American Die Casting Association (NADCA) #207 requirements for Superior high quality H-13 die steel. Standard specification W.nr 1.2344 / AISI H13 / AFNOR Z38 CDV 5.1

    Uddeholm Orvar Supreme

    • Corrosion resistance 30%
    • Wear resistance 80%
    • Polishability 60%
    • Toughness 80%
    Read More
    • Plastic Mould

    Uddeholm Orvar Supreme can be regarded as an “all-round” steel used in several application areas. Except for hot work application areas the steel is also used in moulds for plastics and as a material in high stressed axles. The high degree of purity and the very fine structure shows improvement in dies and components where high mechanical and thermal stresses are involved. Uddeholm Orvar Supreme is produced using the Electro-Slag-Refining (ESR) technique. The ESR process gives Uddeholm Orvar Supreme a high level of homogeneity and cleanliness which results in a high performance hot work tool steel of the highest quality. Benefits Improved tooling performance Uddeholm Orvar Supreme meets the North American Die Casting Association (NADCA) #207 requirements for Superior high quality H-13 die steel. Standard specification W.nr 1.2344 / AISI H13 / AFNOR Z38 CDV 5.1

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  • Uddeholm RoyAlloy

    Uddeholm RoyAlloy is a high-performance stainless mould base tool steel designed to deliver exceptional durability and efficiency in demanding tooling environments. It is developed to meet the requirements of mould bases and moulds where demands on surface finish, service life, and corrosion resistance are more moderate. The material offers an attractive balance between performance, machinability, and cost, making it a competitive option for standard applications in the plastics industry. Benefits Unlike conventional stainless steels, RoyAlloy is supplied in a pre-hardened condition of approximately 30 HRC, eliminating the need for additional heat treatment. This significantly reduces lead times and production costs while ensuring dimensional stability throughout machining and finishing processes. RoyAlloy’s superior corrosion resistance sets it apart in applications where moisture or humid environments can compromise tool life. By minimizing rust and surface degradation, it ensures longer service intervals and reduced maintenance costs. The material’s homogeneous structure and stable mechanical properties provide good dimensional stability and sufficient strength for applications involving short to medium production runs or less demanding plastics. The steel’s weldability and repairability further enhance its value, allowing easy maintenance and extending tool lifespan.

    Uddeholm RoyAlloy

    • Corrosion resistance 60%
    • Wear resistance 30%
    • Polishability 40%
    • Toughness 40%
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    • Plastic Mould

    Uddeholm RoyAlloy is a high-performance stainless mould base tool steel designed to deliver exceptional durability and efficiency in demanding tooling environments. It is developed to meet the requirements of mould bases and moulds where demands on surface finish, service life, and corrosion resistance are more moderate. The material offers an attractive balance between performance, machinability, and cost, making it a competitive option for standard applications in the plastics industry. Benefits Unlike conventional stainless steels, RoyAlloy is supplied in a pre-hardened condition of approximately 30 HRC, eliminating the need for additional heat treatment. This significantly reduces lead times and production costs while ensuring dimensional stability throughout machining and finishing processes. RoyAlloy’s superior corrosion resistance sets it apart in applications where moisture or humid environments can compromise tool life. By minimizing rust and surface degradation, it ensures longer service intervals and reduced maintenance costs. The material’s homogeneous structure and stable mechanical properties provide good dimensional stability and sufficient strength for applications involving short to medium production runs or less demanding plastics. The steel’s weldability and repairability further enhance its value, allowing easy maintenance and extending tool lifespan.

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  • Uddeholm Stavax ESR

    Uddeholm Stavax ESR is a premium stainless mould steel for small and medium inserts and cores. Uddeholm Stavax ESR combines corrosion and wear resistance with excellent polishability, good machinability and stability in hardening. Mould maintenance requirement is reduced by assuring that core and cavity surfaces retain their original finish over extended operating periods. When compared with non stainless mould steel, Uddeholm Stavax ESR offers lower production costs by maintaining rust free cooling channels, assuring consistent cooling and cycle time. This classic stainless tool steel is the right choice when rust in production is unacceptable and where requirements for good hygiene are high, as within the medical industry, optical industry and for other high quality transparent parts. Uddeholm Stavax ESR is a part of the Uddeholm Stainless Concept. Benefits Low mould maintenance because of corrosion resistance: Surfaces retain their original finish Less production during storing and operation in humid condition Lower production costs: Since water-cooling channels are unaffected by corrosion Heat transfer characteristics, and therefore cooling efficiency, are constant throughout the mould life, ensuring consistent cycle times. Long life mould Standard specification W.nr 1.2083 / AISI 420 / AFNOR Z40 CV 14 (RSL)

    Uddeholm Stavax ESR

    • Corrosion resistance 70%
    • Wear resistance 50%
    • Polishability 90%
    • Toughness 50%
    Read More
    • Plastic Mould

    Uddeholm Stavax ESR is a premium stainless mould steel for small and medium inserts and cores. Uddeholm Stavax ESR combines corrosion and wear resistance with excellent polishability, good machinability and stability in hardening. Mould maintenance requirement is reduced by assuring that core and cavity surfaces retain their original finish over extended operating periods. When compared with non stainless mould steel, Uddeholm Stavax ESR offers lower production costs by maintaining rust free cooling channels, assuring consistent cooling and cycle time. This classic stainless tool steel is the right choice when rust in production is unacceptable and where requirements for good hygiene are high, as within the medical industry, optical industry and for other high quality transparent parts. Uddeholm Stavax ESR is a part of the Uddeholm Stainless Concept. Benefits Low mould maintenance because of corrosion resistance: Surfaces retain their original finish Less production during storing and operation in humid condition Lower production costs: Since water-cooling channels are unaffected by corrosion Heat transfer characteristics, and therefore cooling efficiency, are constant throughout the mould life, ensuring consistent cycle times. Long life mould Standard specification W.nr 1.2083 / AISI 420 / AFNOR Z40 CV 14 (RSL)

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  • Uddeholm Tyrax ESR

    Uddeholm Tyrax ESR combines best in class toughness, corrosion and wear resistance. This grade was developed for molding of high performance plastics often filled with glass fiber reinforcements and additives like flame retardants. This matrix- based microstructure is designed to achieve a high-gloss surface by only a few polishing steps, dramatically reducing the tool lead time and enabling production of top quality plastic parts. Uddeholm Tyrax ESR can achieve a high hardness (up to 58 HRC) and is a suitable upgrade from AISI 420 ESR, AISI S7 and AISI 440C. Benefits good dimensional stability at heat treatment and in service even microstructure and small grain size good hardenability Uddeholm Tyrax is also available for Additive Manufacturing, powder for processing Laser Powder Bed Fusion (LPBF) and Laser Metal Deposition (LMD).

    Uddeholm Tyrax ESR

    • Corrosion resistance 80%
    • Wear resistance 80%
    • Polishability 95%
    • Toughness 60%
    Read More
    • Plastic Mould

    Uddeholm Tyrax ESR combines best in class toughness, corrosion and wear resistance. This grade was developed for molding of high performance plastics often filled with glass fiber reinforcements and additives like flame retardants. This matrix- based microstructure is designed to achieve a high-gloss surface by only a few polishing steps, dramatically reducing the tool lead time and enabling production of top quality plastic parts. Uddeholm Tyrax ESR can achieve a high hardness (up to 58 HRC) and is a suitable upgrade from AISI 420 ESR, AISI S7 and AISI 440C. Benefits good dimensional stability at heat treatment and in service even microstructure and small grain size good hardenability Uddeholm Tyrax is also available for Additive Manufacturing, powder for processing Laser Powder Bed Fusion (LPBF) and Laser Metal Deposition (LMD).

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  • Uddeholm Unimax

    Uddeholm Unimax is a high hardness hot work tool steel which provides great wear resistance even over extended time at elevated temperatures. It performs very well in precision forging and hot stamping. Benefits Improved durability and wear resistance in moulding processes that wear hard on the mould like, long run production, moulding of reinforced plastics and compression moulding Longer tool life and a smoother production run with fewer disturbances for maintenance due to the high ductility Problem solver in severe cold work applications where high chipping resistance is required The high hardness and toughness together with the good dimension stability makes Unimax suitable as a substrate steel for surface coating when needed The very good hardenability and the unique properties profile of Unimax make it especially suitable for larger moulds. Unimax is therefore supplied in larger dimensions

    Uddeholm Unimax

    • Corrosion resistance 30%
    • Wear resistance 80%
    • Polishability 80%
    • Toughness 60%
    Read More
    • Plastic Mould

    Uddeholm Unimax is a high hardness hot work tool steel which provides great wear resistance even over extended time at elevated temperatures. It performs very well in precision forging and hot stamping. Benefits Improved durability and wear resistance in moulding processes that wear hard on the mould like, long run production, moulding of reinforced plastics and compression moulding Longer tool life and a smoother production run with fewer disturbances for maintenance due to the high ductility Problem solver in severe cold work applications where high chipping resistance is required The high hardness and toughness together with the good dimension stability makes Unimax suitable as a substrate steel for surface coating when needed The very good hardenability and the unique properties profile of Unimax make it especially suitable for larger moulds. Unimax is therefore supplied in larger dimensions

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  • Uddeholm Vanadis 4 Extra SuperClean

    Uddeholm Vanadis 4 Extra SuperClean is the most versatile pm tool steel on the market today, combining high wear resistance with very good ductility and resistance to chipping of edges. Excellent machinability in both soft and hard condition ensures advantages in both tool making and tool maintenance. Uddeholm Vanadis 4 Extra SuperClean is also available as powder for processing by Electron Beam Melting technology (EBM). This powder has the same chemical composition as the PM material. Benefits Reliable production with low risk of edge chipping Best combination of high hardness, wear resistance and chipping resistance High compressive strength Best stock standard program of all PM grades Standard specification AISI D2 / AFNOR de type Z136 CDV 5.4

    Uddeholm Vanadis 4 Extra SuperClean

    • Corrosion resistance 20%
    • Wear resistance 80%
    • Polishability 80%
    • Toughness 50%
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    • Plastic Mould

    Uddeholm Vanadis 4 Extra SuperClean is the most versatile pm tool steel on the market today, combining high wear resistance with very good ductility and resistance to chipping of edges. Excellent machinability in both soft and hard condition ensures advantages in both tool making and tool maintenance. Uddeholm Vanadis 4 Extra SuperClean is also available as powder for processing by Electron Beam Melting technology (EBM). This powder has the same chemical composition as the PM material. Benefits Reliable production with low risk of edge chipping Best combination of high hardness, wear resistance and chipping resistance High compressive strength Best stock standard program of all PM grades Standard specification AISI D2 / AFNOR de type Z136 CDV 5.4

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  • Uddeholm Vanax SuperClean

    Uddeholm Vanax SuperClean is the long-awaited response to the market’s need for steel that is both strong and stainless. Combining the corrosion resistance of austenitic stainless steel such as AISI 316L, with a hardness of 60 HRC and the wear resistance of a cold work tool steel, opens up new opportunities. Where no previous materials suffice, this powder metallurgical steel grade offers resistance in the most corrosive environments possible. From start to finish, its unique material properties provide reliable performance in the most extreme conditions and for the most demanding working materials. Benefits Uddeholm Vanax SuperClean has an excellent corrosion resistance both in low and high temperature tempered condition in combination with good wear resistance to counteract mixed wear/galling/fretting. Applications are e.g. found in plastic moulding, food processing and engineering designs.

    Uddeholm Vanax SuperClean

    • Corrosion resistance 100%
    • Wear resistance 70%
    • Polishability 80%
    • Toughness 40%
    Read More
    • Plastic Mould

    Uddeholm Vanax SuperClean is the long-awaited response to the market’s need for steel that is both strong and stainless. Combining the corrosion resistance of austenitic stainless steel such as AISI 316L, with a hardness of 60 HRC and the wear resistance of a cold work tool steel, opens up new opportunities. Where no previous materials suffice, this powder metallurgical steel grade offers resistance in the most corrosive environments possible. From start to finish, its unique material properties provide reliable performance in the most extreme conditions and for the most demanding working materials. Benefits Uddeholm Vanax SuperClean has an excellent corrosion resistance both in low and high temperature tempered condition in combination with good wear resistance to counteract mixed wear/galling/fretting. Applications are e.g. found in plastic moulding, food processing and engineering designs.

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