CPM S60V vs M390 Knife Steel Comparison

Comparing CPM-S60V and M390: A Comprehensive Guide for Knife Enthusiasts

Selecting the perfect blade steel can be an exciting yet sometimes overwhelming process—especially when you’re choosing among top-tier stainless steels. Two names you might encounter in the premium arena are CPM-S60V (formerly known as CPM 440V) and M390. Both offer a remarkable mix of edge retention, corrosion resistance, and overall performance, but each also comes with its own quirks. In this post, we’ll take a deep dive into their compositions, heat-treatment insights, performance characteristics, and more—helping you decide which steel might be your best fit.

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1. Introduction to CPM-S60V

CPM-S60V (sometimes referred to as CPM 440V in older literature) is a powder metallurgy (PM) stainless steel produced by Crucible Industries. Through PM processes, the distribution of carbides in the steel is more uniform, which enhances both wear resistance and overall performance compared to conventional steels.

Chemical Composition (Approximate)

• Carbon: ~2.15%
• Chromium: ~17%
• Vanadium: ~5.5%
• Molybdenum: ~0.4%
• Manganese: ~0.4%
• Silicon: ~0.4%

Key Points:

• High carbon content boosts hardness and edge retention.
• Elevated chromium (17%) provides excellent corrosion resistance.
• Significant vanadium content (5.5%) helps form hard vanadium carbides, further improving wear resistance.

Typical Hardness (Rockwell C) Range

• Most blades measure in the 58–61 HRC range.
• Hardness near 60–61 HRC yields outstanding edge retention but makes sharpening more challenging.

Performance Characteristics

• Corrosion Resistance: Excellent
• Toughness: Fair
• Edge Retention: Very Good
• Ease of Sharpening: Fair

Because of the high vanadium and carbon content, CPM-S60V can pose a challenge when sharpening—especially using basic stones. However, diamond or ceramic sharpening tools can handle it effectively.

Heat-Treatment Nuances and Forging

• Requires careful austenitizing temperatures, soak times, and optional cryogenic treatments to reach its full potential in hardness and wear resistance.
• Not particularly known for warping, but overheating can cause grain growth, and overly rapid cooling can introduce stress.

Patina Formation and Protective Coatings

• With about 17% chromium, CPM-S60V is sufficiently stainless; it resists oxidation and seldom forms a patina.
• A light coat of oil or protective treatment is optional but can be beneficial in very humid or salty conditions.

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2. Introduction to M390

M390 is another premier stainless PM steel, produced by Böhler-Uddeholm in Austria. It has become exceptionally popular for its top-tier balance of hardness, corrosion resistance, edge retention, and relative ease of maintenance.

Chemical Composition (Approximate)

• Carbon: ~1.9%
• Chromium: ~20%
• Vanadium: ~4%
• Molybdenum: ~1%
• Tungsten: ~0.6%
• Manganese: ~0.3%
• Silicon: ~0.7%

Key Points:

• The 20% chromium content pushes its corrosion resistance into the “excellent” range.
• Vanadium (~4%) promotes carbide formation, enhancing wear resistance.
• Tungsten helps refine grain structure and contributes to overall edge stability.

Typical Hardness (Rockwell C) Range

• Commonly hardened to 60–62 HRC.
• Some knife makers push it slightly higher (up to 62–63 HRC) for specialized cutting tasks, though at a possible cost to toughness.

Performance Characteristics

• Corrosion Resistance: Excellent
• Toughness: Fair
• Edge Retention: Very Good
• Ease of Sharpening: Good

Heat-Treatment Nuances and Forging

• Like CPM-S60V, M390 benefits from precise, well-managed heat treatment.
• Cryogenic processing (deep freezing) helps reduce retained austenite, boosting hardness and dimensional stability.

Patina Formation and Protective Coatings

• Very high chromium (20%) means M390 resists patina formation.
• Many users love its lustrous finish without needing additional coatings, though protective oil is beneficial in extreme environments.

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3. Side-by-Side Comparison

Below is a quick comparison table summarizing key performance metrics of CPM-S60V and M390:

	CPM-S60V	M390
Corrosion Resistance	Excellent	Excellent
Toughness	Fair	Fair
Edge Retention	Very Good	Very Good
Ease of Sharpening	Fair	Good
Typical HRC Range	~58–61	~60–62

Real-World Performance

• Bushcraft & Survival: Both steels perform well for tasks like feather stick carving and general cutting. However, their fair toughness means they can chip under abuse (e.g., heavy batoning, prying).
• EDC (Everyday Carry): M390’s relatively easier sharpening makes it appealing if you prefer quick touch-ups, while CPM-S60V requires fewer sharpening sessions overall but needs more effort each time.
• Kitchen Use: Both excel here, retaining sharp edges for slicing and chopping while offering strong corrosion resistance.
• Tactical Applications: M390’s fine-grain structure at around 60–62 HRC is renowned for high-end tactical blades. CPM-S60V also excels in repetitive cutting tasks, but its tougher sharpening curve can be a downside in the field.

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4. Ideal Uses and Reasons to Choose

CPM-S60V

• Ideal Uses:

  • Repetitive slicing (e.g., rope, cardboard).
  • EDC knives for users who don’t mind challenging but less frequent sharpening.
  • Collector’s knives that showcase high-end stainless performance.

• Why Pick CPM-S60V?

  • You want outstanding wear resistance and corrosion resistance.
  • You appreciate a slightly more exclusive steel not found in every production lineup.
  • You’re willing to invest in quality sharpening tools (diamond/ceramic) and a bit more time on the bench.

M390

• Ideal Uses:

  • High-end EDC or tactical knives.
  • Premium kitchen cutlery where balance of performance and maintenance is crucial.
  • Users seeking excellent wear and corrosion resistance with easier sharpening than other “super steels.”

• Why Pick M390?

  • Widely hailed as one of the best all-around PM steels available.
  • High availability across many brands and custom knife makers.
  • Great combination of top-tier performance and user-friendliness in sharpening.

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5. Cost, Availability, and Maintenance

Cost

• Both CPM-S60V and M390 are in the higher price range for blade steels.
• M390’s popularity can mean a slightly steadier supply, but it remains firmly a premium option.
• CPM-S60V, while slightly less common, is still found in some custom or mid-level production knives.

Availability

• M390: Broadly adopted by major knife manufacturers—making it easier to find production folders and fixed blades.
• CPM-S60V: More niche, though still offered in certain custom designs.

Ease of Maintenance

• Both steels are highly stainless, requiring minimal upkeep—an occasional wipe-down and optional light lubrication is often enough.
• In extremely humid or salty conditions, applying a protective coat of oil is an extra safeguard.

Sharpening

• CPM-S60V: Fair ease of sharpening; diamond and ceramic stones recommended to handle its harder carbides.
• M390: Good ease of sharpening for a PM steel; still benefits from quality sharpening stones or systems for best results.

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6. Pros and Cons

CPM-S60V

• Pros

  1. Excellent corrosion resistance.
  2. Very good edge retention, especially for repetitive slicing tasks.
  3. Premium performance, adding uniqueness to a collection.

• Cons

  1. Fair toughness—may chip under extreme impact.
  2. Sharpening can be more difficult without the right tools.
  3. Not as widely available as some other steels (e.g., M390, S35VN).

M390

• Pros

  1. Excellent corrosion resistance.
  2. Very good edge retention.
  3. Relatively easier to sharpen compared to other high-carbide PM steels.
  4. Broad adoption by knife makers, leading to greater availability.

• Cons

  1. Fair toughness—like CPM-S60V, not ideal for heavy-duty impact tasks.
  2. Commands a premium price, especially in high-end production or custom knives.

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7. Final Recommendations and Key Takeaways

1. Best for Durability (Between the Two)

   • Both steels have “fair” toughness, so neither is particularly suited for extreme shock or prying. If you need a truly robust steel, consider options like CPM-3V or AEB-L. However, both CPM-S60V and M390 can handle moderate demands well.

2. Best Balance for Everyday Use

   • M390 often takes the crown due to its easier sharpening, outstanding corrosion resistance, and wide availability. It’s a great option if you need to refresh your blade’s edge regularly.

3. If You Value Edge Holding Above All

   • Both CPM-S60V and M390 offer excellent edge retention. CPM-S60V can hold an edge for a very long time under heavy slicing tasks, although the difference can be marginal depending on blade geometry, heat treatment, and usage habits.

4. Collectibility and Rarity

   • CPM-S60V is less common, adding a bit of exclusivity for collectors. If you want a somewhat rarer PM steel, S60V may fit the bill.
   • M390 is recognized worldwide, making it more mainstream but also universally praised.

Ultimately, choosing between CPM-S60V and M390 comes down to personal preference and how you plan to use your knife. If you want a slightly easier sharpening experience and broader availability, M390 is likely your best bet. On the other hand, CPM-S60V shines if you value extreme edge retention in a more niche steel and don’t mind investing in premium sharpening equipment and technique.

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Additional Tips for Knife Enthusiasts

• Consider Steel Equivalents: M390 has near-equivalents like 20CV (Crucible) and CTS-204P (Carpenter). If you see these steels, expect nearly identical performance to M390.
• Invest in Quality Sharpening Tools: Diamond plates or ceramic rods will help you get the most from both CPM-S60V and M390.
• Check Manufacturer Guidelines: For more advanced info on heat treatment or forging, consult the official data sheets from Crucible (CPM-S60V) or Böhler-Uddeholm (M390).

Both CPM-S60V and M390 represent the pinnacle of modern metallurgy for knife enthusiasts. Whether you prioritize relentless edge holding or the convenience of easier sharpening, there’s a configuration out there to satisfy your needs. Review your specific requirements—EDC, tactical, kitchen, or collecting—and choose the steel that best aligns with your expectations. Whichever you pick, you’ll be wielding a blade crafted from some of the most advanced metals available today.