T15 vs T1
These two grades are listed as equivalents of each other: their chemistry windows overlap and they serve the same applications. They are not always identical — check the differences below before substituting, especially in certified designs.
T15
Tool Steel
T15 combines high carbon, about 5% vanadium and 5% cobalt on a 12% tungsten base — the wear-resistance flagship of the conventional T-series. It serves abrasive cutting and cold work where M4-class steels wear too fast.
Standards: DIN 1.3202 · AISI T15 · JIS SKH10 · GB W12Cr4V5Co5
T1
Tool Steel
T1 is the original 18-4-1 tungsten high-speed steel from which the whole HSS family descends. It remains in use for lathe tools and cutters in shops worldwide, and as China’s W18Cr4V and Japan’s SKH2.
Standards: DIN 1.3355 · AISI T1 · JIS SKH2 · GB W18Cr4V
Chemical composition compared (%)
| Element | T15 | T1 |
|---|---|---|
| C | 1.50–1.60 | 0.65–0.80 |
| Si | ≤0.40 | ≤0.40 |
| Mn | ≤0.40 | ≤0.40 |
| Cr | 3.75–5.00 | 3.75–4.50 |
| W | 11.75–13.00 | 17.25–18.75 |
| V | 4.50–5.50 | 0.90–1.30 |
| Co | 4.75–5.25 | — |
Properties compared
| Property | T15 | T1 |
|---|---|---|
| Delivery condition | Annealed | Annealed |
| Hardness (hardened) | 64–67 HRC | 62–65 HRC |
| Density | 8.20 g/cm³ | 8.60 g/cm³ |
| Wear resistance | Extreme (5% vanadium + cobalt) | — |
| Red hardness | — | The original 18-4-1 benchmark |
Sourcing either grade?
Nasteel stocks both families from Shenzhen with EN 10204 3.1 mill certificates by heat number.
Ask for a quotationSee full data sheets: T15 · T1. Substitution decisions for certified parts stay with the design authority.