CPM S90V vs Maxamet Knife Steel Comparison

CPM-S90V vs. Maxamet: A Comprehensive Guide for Knife Enthusiasts and Collectors

In the world of premium knife steels, few names elicit as much excitement among enthusiasts as CPM-S90V and Maxamet. Both are powder-metallurgy steels manufactured using advanced processes that deliver highly refined grain structures, superior wear resistance, and extraordinary cutting performance. Yet, each steel has its own set of strengths and weaknesses that can significantly influence your knife experience, depending on your needs and preferences. In this comprehensive blog post, we’ll explore the finer points of CPM-S90V and Maxamet—covering their chemical compositions, heat-treatment nuances, typical hardness ranges, performance characteristics, cost, availability, and ideal uses. By the end, you’ll have a clear understanding of which steel is best suited to your style—whether you’re an EDC enthusiast, a bushcraft pro, or a collector looking for the newest hard-use steel.

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1. Introduction to CPM-S90V

CPM-S90V is a high-end, powder-metallurgy stainless steel developed by Crucible Industries. It contains approximately 2.3% carbon, 14% chromium, 9% vanadium, and 1% molybdenum, creating a remarkable synergy of corrosion resistance, wear resistance, and high hardness. In terms of edge retention, CPM-S90V is often hailed as one of the top stainless steels on the market.

<details> <summary>Key Takeaways from Section 1</summary>

• Stainless steel with ~14% chromium
• Excels in wear resistance and corrosion resistance
• Typically hardened between 59–61 HRC
• Renowned for excellent edge holding

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Chemical Composition Highlights

• Carbon (2.3%): Boosts hardness and wear resistance.
• Chromium (14%): Ensures very good corrosion resistance and forms carbides.
• Vanadium (9%): Produces exceptionally hard vanadium carbides for wear resistance.
• Molybdenum (1%): Adds to strength and contributes to hardness.

Typical Hardness (Rockwell C) Range

• Often 59–61 HRC, providing a sweet spot between wear resistance and a degree of toughness.

Key Performance Characteristics

• Corrosion Resistance: Very good
• Toughness: Fair
• Edge Retention: Excellent
• Ease of Sharpening: Poor (diamond or quality ceramic stones are recommended)

Example Models: Benchmade 940-1, select Spyderco Sprint Runs (e.g., some Paramilitary 2 variants).

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2. Introduction to Maxamet

Made by Carpenter Technology, Maxamet is a high-speed, powder-metallurgy tool steel that can reach impressively high hardness levels—often 64–68 HRC or even higher with specialized treatments. This extreme hardness makes Maxamet renowned for its exceptional edge retention but comes at the cost of lower toughness. Its composition includes:

• 2.15% carbon
• 4.75% chromium
• 10% cobalt
• 13% tungsten
• 6% vanadium

While its wear resistance is outstanding, its chromium content is lower compared to stainless steels, resulting in only “good” corrosion resistance.

<details> <summary>Key Takeaways from Section 2</summary>

• High-speed tool steel with ultra-high hardness
• Typically hardened between 64–68+ HRC
• Outstanding edge retention, but low toughness
• “Good” (not excellent) corrosion resistance

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Chemical Composition Highlights

• Carbon (2.15%): Enables very high hardness and exceptional edge-holding.
• Chromium (4.75%): Provides moderate corrosion resistance—less than true stainless steels.
• Tungsten (13%): Contributes to extreme hardness and wear resistance.
• Cobalt (10%): Enhances hot hardness, typical in high-speed steels.
• Vanadium (6%): Forms extremely hard carbides that bolster wear resistance.

Typical Hardness (Rockwell C) Range

• Usually 64–68 HRC, making it one of the hardest steels found in production knives.

Key Performance Characteristics

• Corrosion Resistance: Good
• Toughness: Poor
• Edge Retention: Excellent
• Ease of Sharpening: Poor (diamond abrasives almost mandatory)

Example Models: Spyderco Manix 2 Maxamet, Spyderco Para 3 Maxamet.

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3. Detailed Alloy Element Effects

Both CPM-S90V and Maxamet achieve their impressive wear resistance and edge retention through carefully balanced alloying elements:

• Carbon: Both steels have high carbon content, boosting hardness and wear resistance.
• Chromium:
  • CPM-S90V (~14%) is categorized as stainless, ensuring very good corrosion resistance.
  • Maxamet (4.75%) is semi-stainless, meaning it offers protection from rust to a lesser degree.
• Vanadium: High vanadium content in both steels leads to the formation of very hard vanadium carbides.
• Tungsten & Cobalt (in Maxamet): Contribute significantly to hardness and red-hot hardness, essential in high-speed steel applications.

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4. Typical Hardness (Rockwell C) Ranges and Practical Implications

• CPM-S90V (59–61 HRC):

  • Balanced hardness range for general EDC and moderate outdoor tasks.
  • Less frequent chipping compared to ultra-high hardness steels.

• Maxamet (64–68+ HRC):

  • Among the highest hardness levels in knife steels.
  • Offers impressive edge retention but at the expense of toughness.

<details> <summary>Key Takeaways from Section 4</summary>

• Higher hardness typically means longer edge retention.
• Extremely hard steels are more prone to chipping under lateral stress.
• Choose based on the types of tasks you frequently perform.

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5. Heat-Treatment Nuances and Forging

• CPM-S90V:

  • Requires precise temperature control for optimal results.
  • Usually processed via stock-removal methods rather than traditional forging.
  • Less prone to warping and cracking than ultra-hard steels but can still decarburize if mishandled.

• Maxamet:

  • Demands extremely careful heat-treatment (potential multiple normalizing cycles, carefully controlled quenching).
  • Very difficult to forge or differentially heat-treat due to its high hardness and distortion risks.
  • Mistakes in heat treatment can lead to warping or cracking.

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6. Real-World Usage Comparisons

Bushcraft

• Maxamet: Not ideal for batonning or chopping because of poor toughness.
• CPM-S90V: More suitable, although still not as tough as steels specifically designed for heavy impact (e.g., CPM-3V).

Everyday Carry (EDC)

• Both: Offer phenomenal edge retention, reducing the frequency of sharpenings.
• CPM-S90V: More forgiving in corrosive environments (humid, salty, etc.).
• Maxamet: Holds an edge for a very long time but calls for diligent cleaning to prevent rust.

Kitchen Use

• CPM-S90V: Stainless properties make it a great option for kitchen tasks if you prefer minimal maintenance.
• Maxamet: Excellent cutting performance, but more prone to discoloration or rust if not dried promptly.

Survival or Tactical

• Maxamet: Extremely hard edge, but the risk of chipping is higher under heavy impact or prying.
• CPM-S90V: “Fair” toughness allows it to handle more demanding tasks, though it’s still not the best for extreme impact scenarios.

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7. Ease of Sharpening, Wear Resistance, and Chipping Risk

• Ease of Sharpening:

  • Both steels are challenging to sharpen, rating “Poor” in this category.
  • Diamond or high-quality ceramic stones are strongly recommended, along with moderate skill or practice.

• Wear Resistance:

  • Both steels boast exceptional wear resistance, with Maxamet usually taking a slight lead due to its higher achievable hardness.

• Chipping Risk:

  • Maxamet is more prone to chipping under stress due to its extreme hardness.
  • CPM-S90V can still chip, but its fair toughness offers a slight edge in resistance.

<details> <summary>Pro Tip</summary>

For sharpening premium knife steels like CPM-S90V or Maxamet, consider a guided sharpening system (e.g., Wicked Edge or Edge Pro) with diamond stones to ensure consistent angles and reduce frustration.

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8. Corrosion Susceptibility and Patina Formation

• CPM-S90V:

  • With ~14% chromium, corrosion resistance is rated as “very good.”
  • Rarely forms a patina and typically doesn’t require protective coatings unless used in marine or corrosive settings.

• Maxamet:

  • Lower chromium content (~4.75%) means it’s more vulnerable to rust and can develop a patina over time.
  • Regular cleaning, drying, and possibly applying oil or a protective coating (DLC, PVD, etc.) are key to maintaining it.

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9. Cost, Availability, and Maintenance

• Cost:

  • Both are premium steels due to complex powder-metallurgy processes.
  • Maxamet-knives may be slightly more expensive and less common.
  • CPM-S90V is high-cost but seen in a broader range of production and custom knives (e.g., Spyderco, Benchmade).

• Availability:

  • CPM-S90V: Widely offered, including standard runs from top knife brands.
  • Maxamet: Often appears in limited releases or specialized high-end product lines.

• Maintenance:

  • CPM-S90V: Wipe dry and occasionally oil for best results.
  • Maxamet: Requires more vigilance to avoid corrosion—especially after cutting acidic foods or exposure to salty environments.

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10. Ideal Uses and Why Choose These Steels

• CPM-S90V:

  • Best for users seeking top-tier edge retention in a stainless format.
  • Ideal for upscale kitchen knives, EDC folders, and collectors wanting a reliable high-performance cutter.
  • Challenging to sharpen, but it rewards you with fewer sharpenings overall.

• Maxamet:

  • Appeals to those craving extreme hardness and minimal edge rolling.
  • Perfect for light-to-moderate cutting tasks focused on slicing, not prying.
  • Requires meticulous maintenance to prevent corrosion and careful use to avoid chipping.

<details> <summary>Key Takeaways from Section 10</summary>

• CPM-S90V offers a more balanced stainless solution for most practical scenarios.
• Maxamet pushes the envelope on hardness and edge retention but demands more mindful upkeep.

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11. Patina Formation and Protective Coatings

• CPM-S90V:

  • Almost never forms a patina under normal use.
  • Typically doesn’t require special coatings.

• Maxamet:

  • Susceptible to patina and discoloration.
  • Protective coatings (DLC, PVD, Cerakote) or regular oiling can help mitigate rust.

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12. Pros and Cons: CPM-S90V vs. Maxamet

CPM-S90V

• Pros:
  • Very good corrosion resistance
  • Outstanding edge retention
  • Fair toughness (less prone to chipping than ultra-hard steels)
• Cons:
  • Poor ease of sharpening (requires premium abrasives)
  • Not as tough as some other impact-focused steels (e.g., CPM-3V)

Maxamet

• Pros:
  • Extreme edge retention and wear resistance
  • Very high achievable hardness
• Cons:
  • Low toughness (risk of chipping under hard use)
  • Difficult to sharpen without proper equipment
  • Only “good” corrosion resistance (requires thorough cleaning and maintenance)

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13. Comparison Table

Property	CPM-S90V	Maxamet
Typical HRC Range	~59–61 HRC	~64–68+ HRC
Corrosion Resistance	Very Good	Good
Toughness	Fair	Poor
Edge Retention	Excellent	Excellent
Ease of Sharpening	Poor	Poor
Patina Formation	Unlikely	Possible
Ideal Use	EDC, Kitchen, Light	EDC (slicing), Collectors
	Bushcraft	seeking max edge life

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14. Conclusion: Choosing the Right Steel for Your Needs

For knife enthusiasts and collectors who value a balance of stellar edge retention, fair toughness, and stainless qualities, CPM-S90V stands out. Its “very good” corrosion resistance makes it more forgiving in day-to-day use—great for kitchen tasks, EDC in humid conditions, or general outdoors. While sharpening CPM-S90V can be time-consuming, you’ll do it less often owing to its excellent edge stability.

On the other hand, Maxamet occupies the pinnacle of ultra-high hardness and wear resistance, making it a favorite of collectors and steel aficionados eager to test the boundaries of performance. However, its lower corrosion resistance and limited toughness demand careful upkeep and mindful use. If your cutting style is primarily slicing and you’re meticulous with maintenance, Maxamet’s edge will outlast many other steels on the market.

Ultimately, no single steel is perfect for every scenario. CPM-S90V offers a more user-friendly blend of qualities for most knife lovers, while Maxamet caters to extreme performance seekers willing to accept its trade-offs. By understanding your usage patterns, maintenance habits, and personal product preferences, you can confidently pick a steel that will serve you for years—be it the balanced performer of CPM-S90V or the cutting-edge powerhouse of Maxamet.

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Additional Considerations and Recommendations

1. Sharpening Equipment

   • Given both steels’ high carbide content, use diamond plates (e.g., DMT, Atoma) or top-quality ceramic stones.
   • Guided sharpening systems like Wicked Edge or Edge Pro can simplify maintaining a consistent angle.

2. Alternative Steels for Comparison

   • CPM-S110V or M390: Offer excellent corrosion resistance and edge retention, often standing between S90V and Maxamet in overall performance.
   • CPM-3V: Much tougher but sacrifices some corrosion resistance.
   • AEB-L: Known for ease of sharpening and decent toughness, though not at the same level of wear resistance.

3. Factual & Technical Accuracy

   • Refer to official data sheets from Crucible Industries and Carpenter Technology for exact ranges of composition and recommended heat treats.

4. SEO-Friendly Tips

   • Keywords such as “premium knife steels,” “edge retention,” “Rockwell hardness,” and “corrosion resistance” help others discover this guide.

5. Care and Maintenance

   • No matter which steel you choose, don’t neglect basic care: clean, dry, and oil your blade after tough or acidic tasks.

By integrating these notes and best practices alongside your steel selection, you can maximize your knife’s performance and lifespan—whether you lean toward the high-hardness realm of Maxamet or the stainless reliability of CPM-S90V.