S1
Data verifiedS1 is the original tungsten shock-resisting tool steel, built for tools that take repeated hammer blows. Its Cr-W chemistry gives safe hardening with outstanding toughness at working hardness.
Chemical composition
| Element | Content (%) |
|---|---|
| C | 0.40–0.55 |
| Si | 0.15–1.20 |
| Mn | 0.10–0.40 |
| Cr | 1.00–1.80 |
| W | 1.50–3.00 |
| V | 0.15–0.30 |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Delivery condition | Annealed |
| Hardness (hardened) | 50–58 HRC |
| Density | 7.85 g/cm³ |
| Toughness | Excellent (shock-resisting) |
Heat treatment
Harden 860–900 °C oil; temper 200–450 °C depending on impact duty.
Equivalent grades
| Standard | Designation |
|---|---|
| din | 1.2550 (close) |
| aisi | S1 |
| gb | 5CrW2Si (near) |
Compare side by side: S1 vs 1.2550 · S1 vs S7
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Chisels, punches, rivet sets, shear blades, pneumatic tool parts, header dies.
Processing: Deep hardening and forgiving in the oil quench; the default choice where S7-level air hardening is not needed.
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Ask for a quotationVisit NasteelSource: ASTM A681 / EN ISO 4957 published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.