Toolman Special Steels is proud to produce and offer T4 (1.3255) - AISI T4 tool steel is one of tungsten type high speed tool steel, which belongs to ASTM A600 specification, the standard for high speed tool steel materials. ASTM T4 tool steel is similar to T1 Tool Steel materials, but with 4.25~5.75% cobalt added to increase heat resistance. The red hardness of T4 steel and the high temperature hardness is a little higher than T1 tool steel. AISI T4 tool steel is a deep hardening alloy capable of Rockwell C 64 hardness.
Steel Properties
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High duty High-Speed-Steel on tungsten base.
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Deep hardening response
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Good toughness and cutting capability
Chemical Composition
| Element | Value |
|---|---|
| C | 0.81 |
| Cr | 4.30 |
| Mo | 0.65 |
| W | 18.00 |
| Co | 4.80 |
| V | 1.50 |
Mechanical Properties
| Property | Value |
|---|---|
| Hardness (HB) | 265 max (Annealed) |
| Quenching and Tempering Hardness (HRC) | 64 - 65 |
| Poisson’s ratio | 0.27 - 0.30 |
Physical Properties
| Property | Value |
|---|---|
| Density (g/cm³) | 8.7 |
Modulus of Elasticity
| Temperature (°C) | kN/mm² |
|---|---|
| 20 | 217 |
Thermal Properties
| Temperature (℃) | Thermal Expansion Coefficient (10^-6/°C) |
|---|---|
| 500 | 11.3 |
| 600 | 11.4 |
Thermal Conductivity
| Temperature (℃) | Thermal Conductivity (W/m•K) |
|---|---|
| 20 | 19 |
HEAT TREATMENT AND PROCESSES
Heat treatment
| Process | Temperature (°C) | Details |
|---|---|---|
| Soft Annealing | Heat to 820-850°C, slow cool to 550°C, then air cool | Maximum Brinell hardness of 265 |
| Stress Relieving | HHeat to 600-650°C, hold for 1 hour, then air cool | Removes machining stresses to reduce distortion during heat treatment |
| Hardening | Heat to 1260-1290°C, quench in oil, air, or warm bath at 550°C | Hardness after quenching: 63-66 HRC |
| Tempering | 2x at 560-580°C | Hardness after tempering: 64-65 HRC |
| Tempering °C | HRC |
|---|---|
| 100 | 65 |
| 200 | 63 |
| 250 | 62 |
| 300 | 61.5 |
| 400 | 62.5 |
| 500 | 65 |
| 550 | 65.5 |
| 600 | 63 |
| 650 | 55 |
Applications
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Cutting tools
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Broaches and Cold extrusion punches
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Turning
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Planing and Milling cutters for roughing work
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Grey cast iron
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Chill castings NF metals & non-metal material
Quality Assurance
Our T4 1.3255 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 T4 1.3255 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
| ROUNDS | SQUARES | ||
|---|---|---|---|
| SIZE (MM) | CONDITION | SIZE (MM) | CONDITION |
| 6.00 - 14.00 | CG | 7.2, 8.8, 10.5, 11 | HRA |
| 15.00 - 50.00 | HRAP | 13.5, 14, 17.5, 21 | HRA |
| 52.00 - 405.00 | FAT | 27, 32, 40 | HRA |
| 52.00 - 305.00 | FA |
Flats
| THICKNESS | WIDTH | CONDITION |
|---|---|---|
| 5.00 - 32.00 | 21.00 - 105.00 | HRA |
| 32.00 - 105.00 | 40.00 - 205.00 | FA |
Frequently Asked Questions
T4 / DIN 1.3255 / AISI T4 is a tungsten-type high speed tool steel. Toolman states that T4 is similar to T1 but contains 4.25–5.75% cobalt, which increases heat resistance. Its red hardness and high-temperature hardness are described as slightly higher than those of T1.
Toolman describes T4 as a high-duty tungsten-based high speed steel with a deep-hardening response, good toughness and good cutting capability. The grade is also capable of reaching approximately Rockwell C 64 hardness.
We recommend T4 for cutting tools, broaches, cold-extrusion punches, turning tools, planing tools and milling cutters for roughing work. Also, applications involving grey cast iron, chill castings, non-ferrous metals and non-metal materials.
Toolman offers a maximum annealed hardness of 265 HB and a quenching-and-tempering hardness range of 64–65 HRC for T4 steel.
Toolman offers T4 with 0.81% carbon, 4.30% chromium, 0.65% molybdenum, 18.00% tungsten, 4.80% cobalt and 1.50% vanadium.
Toolman offers T4 rounds from 6–405 mm, depending on manufacturing condition. Squares include listed HRA dimensions from 7.2–40 mm and forged-annealed sizes from 52–305 mm. Flats are published from 5–105 mm thickness and 21–205 mm width, depending on condition.
Yes. Our T4 / 1.3255 steel undergoes testing and quality control to support consistent performance and reliability. Certificates and test reports are available upon request for manufacturers and buyers requiring material documentation.
