H21, / DIN 1.2581 , / AISI H21 Steel is a hot work tool steel for oil or air solidifying to grow high hot quality, maintenance of hardness, and warmth checking resistance. These steels have similar characteristics to that of high-speed steels. The primary alloying elements in tungsten hot-work steels include tungsten, chromium, carbon, and vanadium. This alloy produced by Toolman is one of the hot work, tungsten containing tool steels. The tungsten content is beneficial for hot strength at red heat, although toughness is somewhat reduced. This is mostly utilised as hot work devices, instruments for manufacture of hollows, screws, rivets, nuts and bolts. Die casting tools, forming dies, die inserts, hot shear blades.
Steel Properties
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Tungsten containing hot work tool steel beneficial for hot strength at red heat, although toughness is somewhat reduced
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High resistance to the hot tempering and good toughness.
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Very high firmness during the heat and resistance to the tempering
Chemical Composition (Typical Analysis in %)
| Element | C (%) | Si (%) | Mn (%) | P (≤ %) | S (≤ %) | Cr (%) | W (%) | V (%) |
|---|---|---|---|---|---|---|---|---|
| % | 0.26-0.36 | 0.15-0.40 | 0.15-0.40 | 0.030 max | 0.030 max | 3.00-3.75 | 8.50-10.00 | 0.30-0.60 |
Mechanical Properties
| ITEMS | Value |
|---|---|
| Hardness | 40.0 – 55.0 HRC |
| Bulk modulus | 140 GPa |
| Poisson’s ratio | 0.27-0.30 |
| Elastic modulus | 190-210 GPa |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.80 g/cm³ |
| Thermal Conductivity | 27.0 W/m•K |
| Electric Resistivity | 0.52 Ohm•mm²/m |
| Specific Heat Capacity | 0.46 J/g•K |
Modulus of Elasticity
| Property | Value |
|---|---|
| Modulus of Elasticity | 190-210 GPa |
Coefficient of Linear Thermal Expansion
| Temperature Range (°C) | Expansion Coefficient (10⁻⁶ /°C) |
|---|---|
| 20-100 | 11.5 |
| 20-200 | 12.0 |
| 20-300 | 12.2 |
| 20-400 | 12.5 |
| 20-500 | 12.9 |
| 20-600 | 13.0 |
| 20-700 | 13.5 |
Mechanical Properties
| Property | Value |
|---|---|
| Hardness (Annealed) | Max 240 HB |
| Hardness (Quenched) | 47-53 HRC |
HEAT TREATMENT AND PROCESSES
| Soft annealing °C | Cooling | Hardness HB |
|---|---|---|
| 780 – 810 | Slowly | max. 240 |
| Hardening °C | Quenching | Hardness after quenching HRC |
|---|---|---|
| 1000 – 1130 | Oil or hot bath, 600 – 650 °C | 47 -53 |
Tempering
| Tempering °C | HRC |
|---|---|
| 400 | 49 |
| 500 | 49 |
| 550 | 51 |
| 600 | 50 |
| 650 | 46 |
| 700 | 36 |
Applications
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Hot working dies and tooling
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Die casting
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Extrusion
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Hot forming of parts
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Moulds for copper and copper alloys
Quality Assurance
Our H21, / DIN 1.2581 , / AISI H21 steel undergoes rigorous testing and quality control to meet international standards, ensuring consistent performance and reliability. Certificates and test reports are available upon request. Feel free to reach out to us for more information on our H21 steel products or to discuss your specific requirements. We're dedicated to providing top-quality steel solutions that meet your needs and exceed your expectations.
Manufacturing Range
| Products | Diameter (mm) |
|---|---|
| Hot Rolled bar | 8 - 65 |
| Forged and Turned bars | 65.2 - 500 |
| Forged Square Bars | 50 - 500 |
Flats
| THICKNESS | WIDTH |
|---|---|
| 6.00 mm - 410.00 mm | 20.00 mm - 700.00 mm |
Frequently Asked Questions
We manufacture H21 / DIN 1.2581 / AISI H21 as a tungsten-containing hot work tool steel designed for high hot strength, hardness retention and resistance to tempering. Its tungsten content supports strength at red heat, although toughness is somewhat lower than in some other hot work grades.
We supply H21 for hot-working dies and tooling, die casting, extrusion, hot forming of parts, and moulds used for copper and copper alloys. It is also used for tools involved in manufacturing hollows, screws, rivets, nuts and bolts, along with die inserts and hot-shear blades.
Our H21 steel has a maximum annealed hardness of 240 HB and a quenched hardness range of 47–53 HRC. We also publish an overall hardness range of approximately 40–55 HRC, depending on condition and treatment.
We specify soft annealing at 780–810°C and hardening at 1000–1130°C, followed by oil quenching or a hot bath at 600–650°C. Our tempering data ranges from 400°C to 700°C, with hardness varying according to the selected tempering temperature.
Our H21 composition contains 0.26–0.36% carbon, 0.15–0.40% silicon, 0.15–0.40% manganese, 3.00–3.75% chromium, 8.50–10.00% tungsten and 0.30–0.60% vanadium, with phosphorus and sulphur limited to 0.030% each.
We manufacture hot-rolled H21 bars from 8–65 mm diameter, forged and turned bars from 65.2–500 mm, and forged square bars from 50–500 mm. Flats are available from 6–410 mm thickness and 20–700 mm width.
Yes. We subject our H21 steel to rigorous testing and quality control and provide certificates and test reports on request. Manufacturers can also contact our team to discuss grade suitability, dimensions and specific hot-work application requirements.
