S7
Data verifiedS7 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.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.45–0.55 |
| Si | 0.20–1.00 |
| Mn | 0.20–0.90 |
| Cr | 3.00–3.50 |
| Mo | 1.30–1.80 |
| V | ≤0.35 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness (hardened) | 52–60 HRC |
| Density | 7.85 g/cm³ |
| Toughness | Outstanding, air hardening |
Heat treatment
Harden 930–955 °C air; temper 200–540 °C (higher temper for hot-work use).
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.2357 (close) |
| aisi | S7 |
| gb | 5Cr3Mn1SiMo1 (near) |
Compare side by side: S7 vs S1 · S7 vs S5 · S7 vs A2
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Pneumatic chisels, rivet busters, blanking punches, gripper and bending dies, plastic mold cavities needing toughness, shear blades.
Processing: Air hardening makes it safe for intricate tools; machines well annealed. A common answer when D2 or A2 chips in service.
FAQ
- S7 or A2 for a punch that keeps chipping?
- S7 — it trades some abrasive wear life for a large toughness gain, and air hardening keeps distortion low.
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Ask for a quotationVisit NasteelSource: ASTM A681 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.