CPM 15V vs CPM S90V Knife Steel Comparison

CPM 15V vs CPM S90V: A Comprehensive Comparison

If you’re into high-performance knife steels, you’ve likely heard of CPM 15V and CPM S90V—two powder-metallurgy (PM) marvels produced by Crucible Industries. These steels are famous for their exceptional wear resistance and edge retention, largely due to carefully controlled chemistry and PM technology. Whether you’re a knife collector looking for the next exotic steel or a bushcraft enthusiast who demands top-tier performance, understanding the nuances of CPM 15V and CPM S90V is critical.

In this article, we’ll explore each steel in detail, compare their compositions, typical hardness (Rockwell C) ranges, heat-treatment processes, and real-world performance. We’ll also discuss sharpenability, cost, availability, and which steel may best suit specific knife uses. By the end, you’ll have the knowledge needed to decide which steel aligns with your needs and preferences.

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Table of Contents

1. CPM 15V Overview
2. CPM S90V Overview
3. Side-by-Side Comparison
4. Real-World Usage
5. Maintenance, Cost & Availability
6. Pros & Cons
7. Final Recommendations
8. Conclusion
9. FAQ

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CPM 15V Overview

CPM 15V is formulated for extreme wear resistance, thanks to a very high volume of vanadium carbides. However, these carbides also make it more challenging to sharpen and limit its corrosion resistance.

Chemical Composition & Key Elements

• Carbon (~3.4%): Extremely high carbon content for maximum hardness and wear resistance.
• Chromium (~5.25%): Offers some corrosion resistance, but it’s insufficient to be classified as stainless.
• Vanadium (~14.5%): Significantly boosts wear resistance through abundant vanadium carbides.
• Molybdenum (1.3%) & Silicon (0.9%): Enhance toughness and hardenability.

Because of these elements, CPM 15V delivers phenomenal edge retention at the cost of “fair” corrosion resistance and “fair” toughness. Sharpening can be difficult due to the steel’s abrasion resistance.

Typical Hardness (HRC) & Practical Implications

• Range: 62–66 HRC
• Implications: Makers typically choose within this range to balance hardness and chip resistance. Expect extremely long edge life but be prepared to use diamond or CBN stones for sharpening.

Heat Treatment Nuances & Forging

• Austenitizing: Performed at very high temperatures to maximize the formation of wear-resistant carbides.
• Tempering: Often involves multiple cycles to optimize properties and restore some toughness.
• Forging: CPM 15V can be forged but is challenging due to its high carbide volume. Stock removal is more common.

Patina Formation & Protective Coatings

• Corrosion Resistance: “Fair.” The moderate chromium content helps, but it may still rust or develop a patina if neglected.
• Protective Measures: Light oiling or finishes (PVD, DLC, etc.) can prevent rust. Some users allow a natural patina to form as a protective layer.

Ideal Uses

• High-End Collectors: Rare steel prized for its extraordinary performance.
• Woodworking / Whittling: Delivers extended edge retention with repeated slicing.
• Kitchen Knives: If meticulously dried and maintained, it can provide exceptional slicing longevity.

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CPM S90V Overview

CPM S90V marries high wear resistance with genuinely stainless properties, making it a beloved choice for those seeking top-tier performance without the corrosion worries.

Chemical Composition & Key Elements

• Carbon (~2.3%): Supports high hardness and wear resistance.
• Chromium (~14%): Confers stainless status, offering significant corrosion resistance.
• Vanadium (~9%): Produces hard vanadium carbides for excellent wear resistance.
• Molybdenum (~1%): Improves hardenability and refines grain structure.

Although slightly behind CPM 15V in absolute wear resistance, S90V still ranks among the top steels for edge retention while providing better corrosion resistance.

Typical Hardness (HRC) & Practical Implications

• Range: 59–62 HRC
• Implications: Strikes a balance of hardness, edge retention, and moderate toughness, all while remaining stainless. Users find it holds a razor edge for an impressively long time.

Heat Treatment Nuances & Forging

• Austenitizing: Similar high-temperature processes to other advanced CPM stainless steels.
• Tempering: Usually requires multiple temper cycles to balance wear resistance and toughness.
• Forging: Possible but less common. Most makers prefer stock-removal due to the steel’s high carbide content.

Patina Formation & Protective Coatings

• Corrosion Resistance: “Very good.” Typically doesn’t form a patina under normal use.
• Protective Measures: Often unnecessary except in highly corrosive environments (e.g., saltwater). Basic cleaning is usually sufficient.

Ideal Uses

• EDC Knives: Great for regular carry due to its blend of wear resistance and stainless properties.
• Outdoor / Tactical: High corrosion resistance in wet conditions, plus strong edge retention.
• Kitchen Applications: Handles moisture, acids, and quick cleaning without significant staining.

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Side-by-Side Comparison

Attribute	CPM 15V	CPM S90V
Carbon Content	~3.4%	~2.3%
Chromium Content	~5.25% (fair CR)	~14% (very good CR)
Vanadium Content	~14.5%	~9%
Corrosion Resistance	Fair	Very Good
Toughness	Fair	Fair
Edge Retention	Excellent (10/10)	Excellent (9/10)
Ease of Sharpening	Poor	Poor
Typical HRC Range	62–66	59–62
Patina Formation	Possible	Unlikely (stainless)

Key Comparisons

• Corrosion Resistance: S90V easily outperforms 15V in humid or wet conditions.
• Toughness: Both fall into the “fair” category, making them ill-suited for extreme impact or prying.
• Edge Retention: CPM 15V is arguably at the absolute pinnacle, with S90V just a step behind.
• Sharpenability: Both require premium abrasives, especially diamond or CBN, due to high carbide content.

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Real-World Usage

Bushcraft & Survival

• CPM 15V: Delivers unmatched wear resistance but demands vigilant maintenance to avoid rust.
• CPM S90V: Slightly more user-friendly due to its stainless nature and still boasts impressive edge life.

Everyday Carry (EDC)

• CPM 15V: Ideal if you want the longest-lasting edge and don’t mind routine care.
• CPM S90V: More forgiving in everyday scenarios due to its higher corrosion resistance.

Kitchen Use

• CPM 15V: Can hold a razor edge for ages but can rust or form a patina if left wet or exposed to acidic foods.
• CPM S90V: Excellent stainless properties make it a better fit for kitchen moisture and quick cleaning.

Tactical or Military Applications

• CPM 15V: Dominates in pure slicing but is vulnerable to corrosion in harsh conditions.
• CPM S90V: Balances edge durability with stainless benefits, important in field use.

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Maintenance, Cost & Availability

Maintenance

• CPM 15V: Requires care in wet or humid conditions—oiling, protective coatings, or frequent wipe-downs.
• CPM S90V: More straightforward to maintain; basic cleaning and drying typically suffice.

Cost & Availability

• Both steels are premium options, reflected in their price points.
• CPM 15V: Harder to find in production knives; often requires custom orders, leading to higher costs.
• CPM S90V: Still expensive but more prevalent, with major brands offering models in this steel.

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Pros & Cons

CPM 15V

Pros

1. Unparalleled edge retention.
2. Extreme wear resistance for repetitive cutting tasks.
3. Highly sought by collectors for its rarity.

Cons

1. Challenging to sharpen.
2. Corrosion resistance is only fair; can rust or patina if not maintained.
3. Fair toughness; not recommended for impact or prying.
4. Often more expensive and less common in the market.

CPM S90V

Pros

1. Excellent edge retention (just behind 15V).
2. Very good corrosion resistance.
3. Fair toughness suits most slicing and general cutting tasks.
4. More readily available than CPM 15V.

Cons

1. Still difficult to sharpen.
2. Premium price tag, though slightly less than 15V.
3. Fair toughness only; not for heavy impact.

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Final Recommendations

Best for Durability & Toughness?

Neither steel is known for outstanding toughness. If you prioritize impact resistance, look into steels like CPM 3V or simpler carbon steels. Between these two, S90V might offer a more balanced package due to easier maintenance, but both remain in the “fair” toughness range.

Best for Edge Retention?

CPM 15V likely takes top honors here, but S90V is very close. If you demand absolute cutting longevity above all else and can handle the additional maintenance, go for 15V. Otherwise, S90V is more versatile.

Best for Everyday Use & Lower Maintenance?

CPM S90V is the clear winner thanks to its significantly higher corrosion resistance. It’s also more commonly available in production knives, making it a practical choice for the average user.

Ideal Uses Summary

• CPM 15V

  • Specialist tasks needing extreme edge life.
  • Collectors seeking rarity and maximum wear resistance.
  • Users who are meticulous about preventing corrosion.

• CPM S90V

  • All-around high-performance stainless steel for EDC, outdoor, and kitchen use.
  • Excellent choice if you need near-top-level wear resistance with less fuss about rust.

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Conclusion

CPM 15V and CPM S90V represent the pinnacle of modern metallurgy, each delivering extraordinary wear resistance and edge retention. CPM 15V stands out for its unrivaled edge-holding capability, albeit at the expense of easier maintenance and corrosion resistance. CPM S90V, on the other hand, provides a more balanced approach—it’s genuinely stainless and still boasts top-tier edge retention.

Your final pick should reflect your intended usage, willingness to maintain the blade, and budget preferences. Whichever steel you choose, you’ll be wielding a premium material that’s sure to impress both in performance and in discussions with fellow knife enthusiasts.

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FAQ

1. Are CPM 15V and CPM S90V suitable for beginners?
   Both steels can be daunting for beginners due to their sharpening difficulty and higher cost. Starting with a simpler steel (e.g., VG-10, 154CM, or S35VN) might be more beginner-friendly.

2. How do I sharpen these steels effectively?
   High-quality diamond or CBN stones are recommended. These steels contain hard carbides that will quickly wear down less robust sharpening media.

3. Can CPM 15V and CPM S90V be used for large choppers or machetes?
   While possible, they’re not ideal for heavy-impact tools due to their limited toughness. They’re best suited for slicing or controlled tasks.

4. Do these steels require special storage conditions?
   CPM S90V mostly needs simple cleaning and drying. CPM 15V may need light oiling or a protective coating, especially in humid climates or long-term storage.

5. Which steel is better for hunting knives?
   S90V generally wins due to its stainless properties—cleaning game in wet or messy conditions makes corrosion resistance crucial.

By choosing a steel that complements your usage and maintenance style, you’ll maximize your knife’s performance and longevity—be it CPM 15V or CPM S90V, these steels stand among the best the knife world has to offer.