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CPM 4V is a non-stainless powder steel that offers a useful middle ground between very tough grades and steels focused on extreme wear resistance. It has a slightly higher abrasive edge-retention rating than 3V, with a lower toughness rating. That can suit a working knife when both properties matter and you are comfortable caring for a non-stainless blade.
What Is CPM 4V?
CPM 4V is a powder metallurgy tool steel with chromium, molybdenum and vanadium additions. It shares a row with Vanadis 4 Extra in Dr. Thomas’s ratings, but the two keep their own compositions and identities. The table here uses CPM 4V's specification.
Performance Ratings
For the science, we turn to Dr. Larrin Thomas of Knife Steel Nerds, who has kindly allowed us to share his ratings here.
| Property | CPM 4V |
|---|---|
| Abrasive edge retention | |
| Toughness | |
| Corrosion resistance |
Heat treatment, hardness and geometry affect actual knives.
Explore CPM 4V’s Tradeoffs
Choose a steel above to highlight its position and see all three exact ratings below. The full map fits your screen.
High-alloy steel
CPM 4V
- Abrasive edge retention
- 5
- Toughness
- 7
- Corrosion resistance
- 4
Same position; corrosion ratings may differ:
All 48 rated materials. Numbers group steels at identical coordinates; colors describe stainless classification, not corrosion scores. Neither direction means a universally better knife.
CPM 4V’s ratings are shown above. Enable JavaScript to select another steel, or browse the full ratings table.
Edge Retention Compared with 3V
4V scores 5 for abrasive edge retention, compared with 3V at 4.5. That is a modest increase, so it is better treated as a change in balance than a dramatic jump in cutting life. For repeated cutting, the grind and heat treatment still matter alongside the material rating.
The 3V profile explains the alternative if toughness matters more than that modest increase in wear resistance.
How Much Toughness Does 4V Offer?
Its toughness rating is 7, below 3V's 9 but higher than more wear-focused choices such as CPM 10V. That leaves it with useful resistance to fracture without making toughness its only priority. Choose an edge angle and blade design appropriate for the work, especially if the cutting involves harder materials.
Sharpening and Rust Care
Diamond or cubic boron nitride (CBN) abrasives are useful for sharpening 4V. Follow the existing bevel for maintenance, choose a coarser grit for damage and finish with careful burr removal. The abrasive edge-retention rating does not translate directly into a fixed sharpening time.
Its corrosion-resistance rating is 4, and it is not stainless. Wipe away moisture and residue, dry the blade before storage and consider appropriate protection in humid conditions. A coating helps covered surfaces but leaves the cutting edge exposed.
When Would You Choose CPM 4V?
4V is worth considering when you want a balance of toughness and wear resistance and can give the blade regular care. If edge damage dominates your use, look closely at 3V or another toughness-focused option. If prolonged wet exposure is unavoidable, a more corrosion-resistant steel may make ownership easier. Our knife steel guide helps compare the alternatives.
Composition
Our steel composition guide explains what the elements do and how to read these values.
CPM 4V: Niagara/Crucible typical composition, selected elements; not a batch certificate. Niagara Specialty Metals / Crucible: CPM 4V datasheet.
| Element | CPM 4V |
|---|---|
| Carbon (C) | 1.35% |
| Chromium (Cr) | 5% |
| Molybdenum (Mo) | 2.95% |
| Vanadium (V) | 3.85% |
