Toolman Special Steels is proud to produce and offer S1(1.2550) - AISI S1 is an impact resistant tool steel with extremely high toughness, and high hardenability. It can be used for tungsten alloy cold work tools. It is applied for cutting tools for plates, wood-working tool, and blanking dies.
Steel Properties
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High impact resistance
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Good wear resistance
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Good toughness with high strength
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High hardenability
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Shock resisting tool steel with very good toughness in combination with high hardenability.
Chemical Composition
| C | Si | Mn | P | S | Cr | Mo | V | W |
|---|---|---|---|---|---|---|---|---|
| 0.40 - 0.55 | 0.15 - 1.20 | 0.10- 0.40 | 0.03 | 0.03 | 1.00- 1.80 | 0.00 - 0.50 | 0.15 - 0.30 | 1.50 - 3.00 |
Mechanical Properties
| Property | Value |
|---|---|
| Annealing Hardness (HBW) | 229 max |
| Quenching and Tempering Hardness (HRC) | 56 min |
Physical Properties
| Property | Value |
|---|---|
| Density (g/cm³) | 7.86 |
Modulus of Elasticity
| Temperature (°C) | GPa |
|---|---|
| 20 | 190 |
Thermal Properties
| Temperature (℃) | Thermal Expansion Coefficient (10^-6/℃) |
|---|---|
| 20 -100 | 12.4 |
Thermal Conductivity
| Temperature (℃) | Thermal Conductivity (W/m•K) |
|---|---|
| 20 | 41 |
HEAT TREATMENT AND PROCESSES
Heat treatment
| Heat Treatment | Temperature | Duration | Cooling |
|---|---|---|---|
| Stress Relieving | Approx. 650 °C in the annealed state | 1 hour per 50 mm wall thickness | Furnace |
| Soft Annealing | 760 °C | 1 hour per 25 mm wall thickness | Furnace |
| Hardening | 890 °C | 1 minute per mm wall thickness | - |
| Quenching Hardness | Max. 64 HRC | - | in oil, hot bath or vacuum |
| Tempering | See tempering curve | 1 hour per 25 mm wall thickness | Air |
| Working Hardness | 58–62 HRC | - | - |
| Tempering °C after Quenching | HRC |
|---|---|
| 100 | 60 |
| 200 | 58 |
| 300 | 56 |
| 400 | 52 |
| 500 | 48 |
| 600 | 43 |
Applications
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Blanking dies for cutting sheets up to 12 mm thickness
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Trimming and splitting dies
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Cold piercing punches
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Preforming punches
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Shear blades
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Chipping knives
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• Pneumatic chisels
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Coining tools,
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Cold shear blades
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Ejectors
Quality Assurance
Our S1 1.2550 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 S1 1.2550 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 S1 / DIN 1.2550 / AISI S1 as an impact-resistant tool steel with very high toughness and high hardenability. It is suitable for cold work tooling where resistance to shock and impact is important.
We supply S1 for applications such as:
- Blanking dies for sheets up to 12 mm thick
- Trimming and splitting dies
- Cold piercing punches
- Preforming punches
- Shear blades
- Chipping knives
- Pneumatic chisels
- Coining tools
- Cold shear blades
- Ejectors
It is also used for plate-cutting tools and woodworking tools.
Our S1 steel has:
- Maximum annealed hardness: 229 HBW
- Minimum quenching and tempering hardness: 56 HRC
- Maximum quenching hardness: 64 HRC
- Working hardness: 58–62 HRC
Our published heat-treatment guidance includes:
- Stress relieving: approximately 650°C
- Soft annealing: 760°C
- Hardening: 890°C
- Quenching: oil, hot bath or vacuum
- Working hardness: 58–62 HRC
Our tempering data ranges from 60 HRC at 100°C to 43 HRC at 600°C.
Our S1 composition includes:
- Carbon: 0.40–0.55%
- Chromium: 1.00–1.80%
- Tungsten: 1.50–3.00%
- Vanadium: 0.15–0.30%
- Molybdenum: 0.00–0.50%
- Silicon: 0.15–1.20%
- Manganese: 0.10–0.40%
Phosphorus and sulphur are specified at 0.03% each.
Our S1 manufacturing range includes:
- Hot-rolled bars: 8–65 mm diameter
- Forged and turned bars: 65.2–500 mm diameter
- Forged square bars: 50–500 mm
- Flats: 6–410 mm thickness
- Flat widths: 20–700 mm
Yes. We subject our S1 / DIN 1.2550 steel to testing and quality control and provide certificates and test reports on request. Manufacturers can also share their application, size and quantity requirements with us before ordering.
