W1
1.1545 / C100W1 · EN ISO 4957 · 1.1545
W1 (1.1545 / C100W1) is a tool steel (Water-Hardening family) to EN ISO 4957 (1.1545). Nominal carbon content is around 0.95 %. Supplied hardened in service; for analysis treat it as elastic (E = 210 GPa) with a hardness- or fracture-based limit. It is formulated for hardness, wear resistance and dimensional stability in tooling.
Bilinear material model — nonlinear FEA
This grade is supplied hardened in service and is not represented as a bilinear material — it has a negligible uniform-plastic range. Model it as elastic (E = 210 GPa) with an appropriate fracture / hardness-based limit.
Ratings — engineering judgement
Weldabilitypoor
Higher carbon (~0.95%) raises the risk of HAZ cracking — preheat and PWHT are usually required, if welding is advisable at all.
Machinabilitypoor
Machine in the annealed condition; hard and abrasive once heat treated.
Corrosion resistancepoor
No inherent corrosion resistance — protect by paint, galvanising or plating in exposed use.
Hardenabilityexcellent
Designed to through-harden to high hardness for wear and cutting duty.
Toughnesslow
Hard and wear-resistant but low toughness — not for shock loading unless a shock-resisting grade.
Indicative ratings derived from composition and family — engineering guidance, not specification values.
Physical properties
| Density | 7800 | kg/m³ |
| Elastic modulus | 210 | GPa |
| Shear modulus | 80.8 | GPa |
| Poisson's ratio | 0.30 | |
| Thermal expansion | 11.5 | ×10⁻⁶/°C |
| Thermal conductivity | 30 | W/(m·K) |
| Specific heat | 460 | J/(kg·K) |
| Magnetic | Yes |
Typical values for water-hardening steel — use the mill certificate for the specific product.
Chemical composition (wt %)
Nominal composition per EN ISO 4957 for W1 — confirm exact limits against the standard.
Available forms
Common applications
- Cutting, forming and blanking tools
- Dies, punches and moulds
- Wear parts and gauges
History
The cold- and hot-work tool steels are high-carbon, high-alloy steels formulated for hardness, wear resistance and dimensional stability in cutting, forming and die work. The family runs from simple oil- and water-hardening grades to the high-chromium and hot-work die steels.
- 1868Robert Mushet’s self-hardening tungsten tool steel — the ancestor of alloy tool steels
- 1920High-chromium (D-series) cold-work and Cr–Mo hot-work die steels developed
- 1998EN ISO 4957 harmonises the European tool-steel grades
This profile is generated from the grade's core data and family. Composition is decoded from the designation where its naming system defines it; physical properties are family-typical and ratings are indicative. Confirm critical values against the governing standard or the mill certificate. Equivalents, historical designations and hand-written expert notes are added per grade over time.