Hot Work Tool Steels

Tools for hot forming processes require fracture resistance, hot wear resistance and resistance to thermal fatigue. Tempered 3% and 5% CrMoV steels with a hardness of approximately 35 to 55 HRC fulfil these requirements perfectly. Particularly highly stressed tool inserts are also manufactured from maraging steels of the type Fe-18% Ni-Co-Mo-Ti.

Hot‑work tool steels are engineered for extreme thermal and mechanical loads in die casting, forging, hot stamping, and extrusion. Their superior performance is driven by highest purity levels, achieved through advanced remelting technologies such as ESR and VAR, which minimize inclusions and ensure exceptional homogeneity. These steels offer a robust combination of

  • hot wear resistance
  • high hardness
  • compressive strength up to 600 °C
  • thermal shock resistance
  • excellent toughness

making them ideal for demanding hot‑work environments. Thanks to their stability, durability, and availability in large dimensions, they also perform strongly in selected cold‑work and plastics processing applications. By selecting the right BÖHLER or Uddeholm grade, manufacturers can significantly extend tool life, reduce thermal fatigue and cracking, and achieve a lower cost per produced part. Developed in the dedicated tool steel mills in Kapfenberg (Austria) and Hagfors (Sweden), these high‑performance materials set global benchmarks in hot‑work tooling efficiency, reliability, and tool life.

Related Products

  • BÖHLER W300 ISOBLOC

    BÖHLER W300 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2343 (X37CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as good hot hardness and very good resistance against heat-checkings. The combination of these properties makes it a top performer in high- and low-pressure die casting as well as in closed-die and open-die forging. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.

    BÖHLER W300 ISOBLOC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • AISI H11
    • EN X37CrMoV5-1
    • JIS SKD6
    • NADCA D1830
    • SEL 1.2343
    • UNS T20811
    • EN ISO 4957
    • JIS G4404
    • NADCA #207

    BÖHLER W300 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2343 (X37CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as good hot hardness and very good resistance against heat-checkings. The combination of these properties makes it a top performer in high- and low-pressure die casting as well as in closed-die and open-die forging. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.

    Read More
  • BÖHLER W300 ISODISC

    BÖHLER W300 ISODISC is a 5% chromium steel and corresponds to material number 1.2343 (X37CrMoV5-1). This common tool steel has good hot toughness as well as a high hot hardness and a high resistance against heat-checkings. The combination of these properties makes it a standard choice in extrusion, forging and low-pressure die casting. This material is also available as W300 ISOBLOC which is a remelted grade with improved cleanliness, homogeneity and toughness.

    BÖHLER W300 ISODISC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • AISI H11
    • EN X37CrMoV5-1
    • JIS SKD6
    • SEL 1.2343
    • UNS T20811
    • EN ISO 4957
    • JIS G4404

    BÖHLER W300 ISODISC is a 5% chromium steel and corresponds to material number 1.2343 (X37CrMoV5-1). This common tool steel has good hot toughness as well as a high hot hardness and a high resistance against heat-checkings. The combination of these properties makes it a standard choice in extrusion, forging and low-pressure die casting. This material is also available as W300 ISOBLOC which is a remelted grade with improved cleanliness, homogeneity and toughness.

    Read More
  • BÖHLER W302 ISOBLOC

    BÖHLER W302 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as very high hot hardness and a very good resistance against heat-checkings. The combination of these properties makes it a top performer in closed- and open-die forging as well as in high- and low-pressure die casting. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.

    BÖHLER W302 ISOBLOC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • AISI H13
    • EN X40CrMoV5-1
    • JIS SKD61
    • NADCA B1885
    • SEL 1.2344
    • UNS T20813
    • EN ISO 4957
    • JIS G4404
    • NADCA #207

    BÖHLER W302 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as very high hot hardness and a very good resistance against heat-checkings. The combination of these properties makes it a top performer in closed- and open-die forging as well as in high- and low-pressure die casting. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.

    Read More
  • BÖHLER W302 ISODISC

    BÖHLER W302 ISODISC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). This common tool steel has good hot toughness as well as a high hot hardness and a high resistance against heat-checkings. The combination of these properties makes it a standard choice in extrusion, forging and low-pressure die casting. This material is also available as W302 ISOBLOC which is a remelted grade with improved cleanliness, homogeneity and toughness.

    BÖHLER W302 ISODISC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • AISI H13
    • EN X40CrMoV5-1
    • JIS SKD61
    • SEL 1.2344
    • UNS T20813
    • EN ISO 4957
    • JIS G4404

    BÖHLER W302 ISODISC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). This common tool steel has good hot toughness as well as a high hot hardness and a high resistance against heat-checkings. The combination of these properties makes it a standard choice in extrusion, forging and low-pressure die casting. This material is also available as W302 ISOBLOC which is a remelted grade with improved cleanliness, homogeneity and toughness.

    Read More
  • BÖHLER W303 ISODISC

    BÖHLER W303 ISODISC is a 5% chromium steel and corresponds to material number 1.2367 (X38CrMoV5-3). This tool steel has good hot toughness as well as a very high hot hardness and resistance against heat-checkings. Compared to an X37CrMoV5-1 (material number 1.2343), the steel has an increased molybdenum content, which significantly increases its thermal resistance and thus makes it the ideal material in die closed-die forging, open-die forging and extrusion.

    BÖHLER W303 ISODISC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • EN X38CrMoV5-3
    • SEL 1.2367
    • EN ISO 4957

    BÖHLER W303 ISODISC is a 5% chromium steel and corresponds to material number 1.2367 (X38CrMoV5-3). This tool steel has good hot toughness as well as a very high hot hardness and resistance against heat-checkings. Compared to an X37CrMoV5-1 (material number 1.2343), the steel has an increased molybdenum content, which significantly increases its thermal resistance and thus makes it the ideal material in die closed-die forging, open-die forging and extrusion.

    Read More
  • BÖHLER W320 ISODISC

    BÖHLER W320 ISODISC is a 3% chromium steel and corresponds to material number 1.2365 (32CrMoV12-28). This tool steel has good hot toughness as well as a very high hot hardness and resistance against heat-checkings. Compared to an X37CrMoV5-1 (material number 1.2343), the steel has an increased molybdenum content, which significantly increases its thermal resistance and thus makes it the ideal material in die closed- and open-doe forging. Due to the lower chromium content, reduced through-hardenability occurs which limits its applications to rather smaller tools.

    BÖHLER W320 ISODISC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • AISI ~H10
    • EN 32CrMoV12-28
    • JIS SKD7
    • SEL 1.2365
    • UNS ~T20810
    • EN ISO 4957
    • JIS G4404

    BÖHLER W320 ISODISC is a 3% chromium steel and corresponds to material number 1.2365 (32CrMoV12-28). This tool steel has good hot toughness as well as a very high hot hardness and resistance against heat-checkings. Compared to an X37CrMoV5-1 (material number 1.2343), the steel has an increased molybdenum content, which significantly increases its thermal resistance and thus makes it the ideal material in die closed- and open-doe forging. Due to the lower chromium content, reduced through-hardenability occurs which limits its applications to rather smaller tools.

    Read More
  • BÖHLER W350 ISOBLOC

    BÖHLER W350 ISOBLOC is a material produced by the electroslag remelting process (ESR) which is particularly suitable for use in large casting and forging molds. Although the steel can be classified as a 5% chromium steel, the chemical composition has been chosen to provide the best possible through-hardenability without any loss of toughness or resistance against heat-checkings. These properties make the steel the perfect choice to produce very large die casting molds, for example for mega- or giga-casting.

    BÖHLER W350 ISOBLOC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • Market grade BÖHLER patent
    • NADCA E1850
    • NADCA #207

    BÖHLER W350 ISOBLOC is a material produced by the electroslag remelting process (ESR) which is particularly suitable for use in large casting and forging molds. Although the steel can be classified as a 5% chromium steel, the chemical composition has been chosen to provide the best possible through-hardenability without any loss of toughness or resistance against heat-checkings. These properties make the steel the perfect choice to produce very large die casting molds, for example for mega- or giga-casting.

    Read More
  • BÖHLER W360 ISOBLOC

    BÖHLER W360 ISOBLOC is a material produced by the electroslag remelting process (ESR), which has been specially adapted for use at high tool hardnesses in the range of 51-57 HRC. Although the steel can be classified as a 5% chromium steel, the increased carbon and molybdenum content coupled with state-of-the-art manufacturing technology ensures that BÖHLER W360 ISOBLOC still shows a very good toughness and an exceptionally good thermal resistance, even at high hardness levels. These properties make the steel the perfect choice for smaller components in the die casting sector (e.g., mold inserts, cores, core pins, ejector pins, etc.). The material also is frequently the preferred choice for closed-die and open-die forging tools due to its high wear resistance. Because of this excellent wear resistance and the high toughness, BÖHLER W360 ISOBLOC is also frequently used for cold work applications and as a molding material for plastic injection molds. The Steel also is available as powder material for metal-3D-printing under the brand name BÖHLER W360 AMPO.

    BÖHLER W360 ISOBLOC

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • Market grade BÖHLER patent

    BÖHLER W360 ISOBLOC is a material produced by the electroslag remelting process (ESR), which has been specially adapted for use at high tool hardnesses in the range of 51-57 HRC. Although the steel can be classified as a 5% chromium steel, the increased carbon and molybdenum content coupled with state-of-the-art manufacturing technology ensures that BÖHLER W360 ISOBLOC still shows a very good toughness and an exceptionally good thermal resistance, even at high hardness levels. These properties make the steel the perfect choice for smaller components in the die casting sector (e.g., mold inserts, cores, core pins, ejector pins, etc.). The material also is frequently the preferred choice for closed-die and open-die forging tools due to its high wear resistance. Because of this excellent wear resistance and the high toughness, BÖHLER W360 ISOBLOC is also frequently used for cold work applications and as a molding material for plastic injection molds. The Steel also is available as powder material for metal-3D-printing under the brand name BÖHLER W360 AMPO.

    Read More
  • BÖHLER W400 VMR

    BÖHLER W400 VMR is a vacuum remelted material specially developed for tools with complex structures. The steel can be assigned to the 5% chromium steels and has a very high purity due to the special manufacturing technology. Because of its high degree of purity, the excellent homogeneity and the special alloying concept, BÖHLER W400 VMR is one of the hot work tool steels with the highest reachable toughness values. Therefore, this material is a problem solver in many areas when standard grades are no longer sufficient. In addition, Böhler W400 VMR has outstanding polishability. For this reason, the steel is also popular as a molding material for plastic injection molds.

    BÖHLER W400 VMR

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • AISI ~H11
    • EN ~X37CrMoV5-1
    • NADCA E1810
    • SEL 1.2340
    • UNS ~T20811
    • NADCA #207

    BÖHLER W400 VMR is a vacuum remelted material specially developed for tools with complex structures. The steel can be assigned to the 5% chromium steels and has a very high purity due to the special manufacturing technology. Because of its high degree of purity, the excellent homogeneity and the special alloying concept, BÖHLER W400 VMR is one of the hot work tool steels with the highest reachable toughness values. Therefore, this material is a problem solver in many areas when standard grades are no longer sufficient. In addition, Böhler W400 VMR has outstanding polishability. For this reason, the steel is also popular as a molding material for plastic injection molds.

    Read More
  • BÖHLER W403 VMR

    BÖHLER W403 VMR is a vacuum remelted material which was developed as a problem solver for tools for where a standard solution is no longer sufficient. The steel can be assigned to the 5% chromium steels and has a very high purity due to the special manufacturing technology. In addition, the increased molybdenum content leads to improved thermal resistance as well as wear resistance, which makes BÖHLER W403 VMR an all-rounder that is often used for highly stressed dies in the die casting sector. In addition, Böhler W403 VMR has outstanding polishability. For this reason, the steel is also popular as a molding material for plastic injection molds.

    BÖHLER W403 VMR

    High temperature toughness
    High temperature wear resistance
    Machinability in as supplied condition
    Polishability
    Read More
    • Hot Work
    • EN ~X38CrMoV5-3
    • NADCA C1885
    • SEL ~1.2367
    • NADCA #207

    BÖHLER W403 VMR is a vacuum remelted material which was developed as a problem solver for tools for where a standard solution is no longer sufficient. The steel can be assigned to the 5% chromium steels and has a very high purity due to the special manufacturing technology. In addition, the increased molybdenum content leads to improved thermal resistance as well as wear resistance, which makes BÖHLER W403 VMR an all-rounder that is often used for highly stressed dies in the die casting sector. In addition, Böhler W403 VMR has outstanding polishability. For this reason, the steel is also popular as a molding material for plastic injection molds.

    Read More
  • BÖHLER W460 VMR

    BÖHLER W460 VMR is a double vacuum arc remelted (VAR) material that has been specially adapted for use in the motorsport sector. The steel purity achieved by this special manufacturing technology, combined with the high strength, ensures that a very high fatigue strength can be guaranteed. The high purity also results in very good polishability, which makes the steel a good choice as a tool material for minting coins.

    Read More
    • Hot Work
    • Automotive
    • Market grade BÖHLER patent

    BÖHLER W460 VMR is a double vacuum arc remelted (VAR) material that has been specially adapted for use in the motorsport sector. The steel purity achieved by this special manufacturing technology, combined with the high strength, ensures that a very high fatigue strength can be guaranteed. The high purity also results in very good polishability, which makes the steel a good choice as a tool material for minting coins.

    Read More
  • BÖHLER W720 VMR

    BÖHLER W720 VMR is not a classic hot work tool steel, but an ultra-high strength maraging steel. Compared to quenched and tempered steels, the material generates its high strength not through a hardened and tempered martensitic structure with a high carbon content and secondary hardening carbides, but through the precipitation of intermetallic phases from a tough nickel martensitic matrix. BÖHLER W720 VMR corresponds to material number 1.6358 (X2NiCoMoTi18-9-5) and has proven to be ideally suited for many tool steel applications in cold and hot work (e.g., for extrusion stems) up to 450 °C.

    Read More
    • Hot Work
    • SEL 1.6358
    • UNS K93120

    BÖHLER W720 VMR is not a classic hot work tool steel, but an ultra-high strength maraging steel. Compared to quenched and tempered steels, the material generates its high strength not through a hardened and tempered martensitic structure with a high carbon content and secondary hardening carbides, but through the precipitation of intermetallic phases from a tough nickel martensitic matrix. BÖHLER W720 VMR corresponds to material number 1.6358 (X2NiCoMoTi18-9-5) and has proven to be ideally suited for many tool steel applications in cold and hot work (e.g., for extrusion stems) up to 450 °C.

    Read More
  • BÖHLER W751

    BÖHLER W751 ISOBLOC is not a classic hot work tool steel, but a hardenable steel with an austenitic structure. Compared to quenched and tempered steels, the material does not generate its strength through a hardening structure with high carbon content and secondary hardening carbides, but through the precipitation of intermetallic phases from a tough austenitic matrix. BÖHLER W751 ISOBLOC is a chemically modified version of material number 1.2779 (X6NiCrTi26-15) and has proved to be ideally suited for many tool steel applications in cold and hot work (e.g., for extrusion liners) up to 750 °C and is therefore an economic alternative to superior nickel base alloys.

    Read More
    • Hot Work
    • EN ~X6NiCrTi26-15
    • SEL ~1.2779

    BÖHLER W751 ISOBLOC is not a classic hot work tool steel, but a hardenable steel with an austenitic structure. Compared to quenched and tempered steels, the material does not generate its strength through a hardening structure with high carbon content and secondary hardening carbides, but through the precipitation of intermetallic phases from a tough austenitic matrix. BÖHLER W751 ISOBLOC is a chemically modified version of material number 1.2779 (X6NiCrTi26-15) and has proved to be ideally suited for many tool steel applications in cold and hot work (e.g., for extrusion liners) up to 750 °C and is therefore an economic alternative to superior nickel base alloys.

    Read More

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