S7 vs A2
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.
S7
Tool Steel
S7 is an air-hardening shock-resisting steel with 3.25% chromium and molybdenum, combining S-class toughness with low distortion and some hot hardness. It bridges cold work, impact tooling and light hot work.
Standards: DIN 1.2357 (close) · AISI S7 · GB 5Cr3Mn1SiMo1 (near)
A2
Tool Steel
A2 is an air-hardening 5% chromium cold work steel with much better toughness than D2 and far less distortion than oil-hardening grades. It is the default upgrade from O1 where die size or intricate shapes make quench cracking a risk.
Standards: DIN 1.2363 · AISI A2 · JIS SKD12 · GB Cr5Mo1V
Chemical composition compared (%)
| Element | S7 | A2 |
|---|---|---|
| C | 0.45–0.55 | 0.95–1.05 |
| Si | 0.20–1.00 | 0.10–0.50 |
| Mn | 0.20–0.90 | 0.40–1.00 |
| Cr | 3.00–3.50 | 4.75–5.50 |
| Mo | 1.30–1.80 | 0.90–1.40 |
| V | ≤0.35 | 0.15–0.50 |
Properties compared
| Property | S7 | A2 |
|---|---|---|
| Delivery condition | Annealed | Annealed |
| Hardness (hardened) | 52–60 HRC | 57–62 HRC |
| Density | 7.85 g/cm³ | 7.85 g/cm³ |
| Toughness | Outstanding, air hardening | Good for cold work |
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: S7 · A2. Substitution decisions for certified parts stay with the design authority.