W6Mo5Cr4V2Co5 — W6Mo5Cr4V2Co5 Cobalt High-Speed Steel — is a cobalt high-speed steel supplied at HRC 63-66. Its chemistry centres on 0.85-0.95% carbon, 3.80-4.50% chromium, 4.50-5.50% molybdenum, 1.75-2.20% vanadium and 4.50-5.50% cobalt. 5% cobalt content — outstanding red hardness. It is available from stock as precision-ground hardened round bar from Φ2 to Φ100 mm, and as machined rotary die bodies made to drawing.
What W6Mo5Cr4V2Co5 is, and where it fits
Grade selection is about matching the dominant failure mode. W6Mo5Cr4V2Co5's role in the range is clear: red hardness for long high-speed runs. If your dies fail by gradual wear, prioritise wear resistance. If they chip or crack, prioritise toughness — which usually means accepting a slightly lower hardness.
- GB (China)
- W6Mo5Cr4V2Co5
- AISI / ASTM (US)
- M35 / T11335
- JIS (Japan)
- SKH55
- DIN / W-Nr (Germany)
- 1.3243 / HS6-5-2-5
- NF / AFNOR (France)
- HS6-5-2-5
- UNI (Italy)
- HS6-5-2-5
- GOST (Russia)
- R6M5K5
Working hardness and what each band is for
W6Mo5Cr4V2Co5 hardens across a wide window, and the hardness you choose changes the tool's behaviour more than the grade does. Higher hardness buys wear resistance and edge retention at the cost of toughness; lower hardness does the reverse.
| Band | Hardness | Typical use |
|---|---|---|
| Primary working range | 63 - 66 | First choice for standard production tooling |
| Secondary range | 60 - 63 | Where the application calls for more toughness or more wear resistance |
W6Mo5Cr4V2Co5 for hardened round bar and rotary dies
| Product line | Suitability | Working hardness | Typical applications |
|---|---|---|---|
| hardened round bar | Recommended (4/5) | HRC 63-66 | High-speed cutting dies, Precision circular blades, Wear-resistant die tooling |
| custom rotary dies | Recommended (5/5) | HRC 63-66 | High-speed rotary dies, Precision slitting rollers, Long-life die rollers |
When to choose W6Mo5Cr4V2Co5 — and when not to
| Choose W6Mo5Cr4V2Co5 when… | Look at another grade when… |
|---|---|
| Long production runs on carton board where re-sharpening intervals drive cost | The failure mode is chipping — W6Mo5Cr4V2 or Cr8Mo2SiV will outlast it |
| Edge temperatures exceed what W6Mo5Cr4V2 can hold without softening | Grinding capacity is limited; cobalt grades are noticeably harder to grind |
| You want cobalt performance with more toughness than W2Mo9Cr4VCo8 offers |
Related grades and guides for W6Mo5Cr4V2Co5
- W6Mo5Cr4V2Compare W6Mo5Cr4V2Co5 against W6Mo5Cr4V2
- W2Mo9Cr4VCo8Compare W6Mo5Cr4V2Co5 against W2Mo9Cr4VCo8
- W6Mo5Cr4V2, Co5 & W2Mo9Cr4VCo8 Compared6 min read · Die Material Selection
- Rotary Die Maintenance & Resharpening Guide7 min read · Rotary Die Tooling
- Which industries use W6Mo5Cr4V2Co5?Packaging · Slitting
W6Mo5Cr4V2Co5 FAQ
W6Mo5Cr4V2Co5 (W6Mo5Cr4V2Co5 Cobalt High-Speed Steel) is used for high-speed cutting, red hardness, wear-resistant applications. 5% cobalt content — outstanding red hardness In practice it is supplied as hardened round bar for die making and as machined rotary die bodies, at 63-66 in normal production.