CPM S30V Tool Steel
A powder-metallurgy martensitic stainless steel, for wear and corrosion resistance
Typical values for the temper in the title
CPM S30V is a powder-metallurgy martensitic stainless steel, with about 14% chromium, 4% vanadium and 2% molybdenum. Unlike 440C, where wear resistance comes from chromium carbides, here vanadium forms harder carbides. More chromium remains in the matrix, so corrosion resistance is better.
It was originally developed for knives, and is also used for wear parts in the food and chemical industries, where both wear and corrosion resistance are needed.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Modulus of elasticity E | 200 GPa | |
| Density ρ | 7.65 g/cm³ | |
| Machinability | 30% (annealed) | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Cr chromium | about 14.0 (typical) | corrosion resistance |
| V vanadium | about 4.0 (typical) | hard vanadium carbides |
| Mo molybdenum | about 2.0 (typical) | corrosion resistance |
| C carbon | about 1.45 (typical) | hardness and carbides |
| Fe iron | balance |
Typical composition per the Crucible data sheet. This is a Crucible proprietary steel.
Heat treatment
Tool steel is sold annealed, machined in that state, then hardened and tempered. Temperatures and hardness in the table are typical values from producer data sheets.
| Step / condition | Values | Notes |
|---|---|---|
| Annealed | for machining | |
| Hardening | typically 1040–1095 °C (per the producer data sheet) | in a vacuum furnace |
| Temper | to target | high hardness |
Applications
- Quality knives
- Wear parts in the food industry
- Chemical industry parts
- Valves and pump parts
- Corrosion-resistant cutting tools
Fabrication
Heat treatment
In a vacuum furnace, per the producer data sheet.
Grinding
Relatively difficult, because of the vanadium carbides.
Corrosion
Better than 440C, but still a martensitic stainless: not for harsh marine environments.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| 440C | 760–1900 / 450–1860 MPa | Not recommended | an ordinary martensitic stainless, cheaper · material page |
| D2 | 800 MPa anneal / — | Not recommended | a tool steel, not stainless · material page |
| CPM 10V | — / — | Poor | more wear resistant, not for corrosion · material page |
Common mistakes
Using it in a harsh marine environment
It is a martensitic stainless. In seawater it may stain and pit.
Hardening without a vacuum furnace
The surface decarburizes and properties suffer.
Treating it as an ordinary tool steel
It is a stainless, with corrosion resistance, and behaves differently in heat treatment.
Equivalents, standards and supply
| Standards | Crucible Industries Proprietary / AMS 5934 |
|---|---|
| Forms | plate · wire (cutlery) |
| Producers | Crucible Industries · Böhler M390 (similar) |
Learn more
Values are typical and for comparison only. Actual hardness depends on hardening temperature, section size and tempering. For design, rely on the standard, the producer data sheet and the mill certificate. Sources: ASTM A681 and A600, ISO 4957, and producer data sheets (Crucible, Niagara, Alro).
Updated: October 31, 2026