Toolman Special Steels is proud to produce and offer M42 (1.3247) - a high speed cobalt alloy steel that is regularly manufactured. When compared to traditional high speed steel, it has outstanding thermal hardness so that it is suitable for higher cutting speeds or extends the time before the cutting tool needs replacement.
Steel Properties
-
Good high temperature hardness
-
High wear resistance
-
High cutting ability
-
High impact resistance
-
Fine and uniform grain size
-
Good grindability due to lower V - content.
Chemical Composition
| Element | Value |
|---|---|
| C | 1.10 |
| Cr | 3.90 |
| Mo | 9.20 |
| W | 1.40 |
| Co | 7.80 |
| V | 1.20 |
Mechanical Properties
| Property | Value |
|---|---|
| Hardness (HBW) | 269 max (Annealed) |
| Quenching and Tempering Hardness (HRC) | 66 min |
Physical Properties
| Property | Value |
|---|---|
| Density (g/cm³) | 8.3 |
Modulus of Elasticity
| Temperature (°C) | kN/mm² |
|---|---|
| 20 | 225 |
Thermal Properties
| Temperature (℃) | Thermal Expansion Coefficient (10^-6/℃) |
|---|---|
| 500 | 12.4 |
| 600 | 12.5 |
Thermal Conductivity
| Temperature (℃) | Thermal Conductivity (W/m•K) |
|---|---|
| 20 | 19 |
HEAT TREATMENT AND PROCESSES
Heat treatment
| Process | Details |
|---|---|
| Decarburization | Use rectified salt baths or proper atmosphere control in furnace hardening to avoid decarburization. |
| Normalizing | Not recommended. |
| Hardening | Preheat at 1500/1600°F (816/871°C) thoroughly. Transfer to high heat of 2150/2200°F (1177/1204°C) in salt or 25°F (14°C) higher in atmosphere furnaces.Quench in salt at 1000/1150°F (538/621°C) until equalised, then cool in air. Alternatively, quench in warm oil. Cool to 150°F (66°C) max before tempering. |
| Deformation | Size change is minimal during hardening. When hardened from 2175°F (1191°C) in salt, a 1" (25.4 mm) cube expands about 0.0005" (0.013 mm). Expands similarly when tempered at 1000°F (538°C). |
| Tempering | Temper between 950°F (510°C) and 1100°F (593°C). Tempering below 1000°F (538°C) not recommended. Use triple temper cycle with a minimum of two hours at temperature each time. Cool to room temperature after each cycle. |
| Tempering °C | HRC |
|---|---|
| 200 | 62.5 |
| 300 | 61 |
| 400 | 61.5 |
| 500 | 66.5 |
| 520 | 68 |
| 560 | 67 |
| 600 | 64 |
| 650 | 50 |
| 700 | 42 |
Applications
-
Drills
-
Hobs
-
Taps
-
End mills
-
Milling cutters
-
Form and gear Cutters
-
Broaches and Chasers
Counterbores
Trimming Dies
Quality Assurance
Our M42 1.3247 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 M42 1.3247 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
M42 / DIN 1.3247 / AISI M42 is a high-speed cobalt-alloy steel. It has outstanding thermal hardness, which makes it suitable for higher cutting speeds or for extending the operating period before cutting-tool replacement. It also offers high wear resistance and high cutting ability.
We offer M42 for drills, hobs, taps, end mills, milling cutters, form cutters, gear cutters, broaches, chasers, counterbores and trimming dies. These applications make M42 particularly relevant to manufacturers producing high-performance cutting and forming tools.
A maximum annealed hardness of 269 HBW and a minimum quenching-and-tempering hardness of 66 HRC. Its tempering table shows a maximum value of 68 HRC at 520°C under the stated tempering conditions.
Tempering below 538°C (1000°F) is not recommended. We recommend a triple temper cycle, with a minimum of two hours at temperature during each cycle and cooling to room temperature after every cycle.
Our published chemical composition includes M42 with 1.10% carbon, 3.90% chromium, 9.20% molybdenum, 1.40% tungsten, 7.80% cobalt and 1.20% vanadium.
Toolman lists M42 rounds from 6–405 mm, depending on manufacturing condition. Squares include listed HRA sizes from 7.2–40 mm and forged-annealed sections from 52–305 mm. Flats are published from 5–105 mm thickness and 21–205 mm width, depending on condition.
Yes. Our M42 / 1.3247 steel undergoes rigorous testing and quality control. Certificates and test reports are available upon request, enabling manufacturers and procurement teams to request supporting quality documentation for supplied material.
