CPM S110V vs M398 Knife Steel Comparison

CPM S110V vs M398: Which Super Steel is Right for You?

Below is a comprehensive look at two high-performance, powder-metallurgy steels that have become favorites among serious knife enthusiasts: CPM-S110V and M398. Understanding their composition, heat-treatment protocols, typical Rockwell hardness ranges, and real-world performance characteristics can help you decide which steel is better suited to your needs. Whether you’re into bushcraft, everyday carry (EDC), kitchen prep, survival, or tactical use, this guide offers an in-depth comparison so you can make an informed choice.

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1. Introduction to CPM-S110V and M398

Both CPM-S110V and M398 are premium “super steels” produced through powder metallurgy — a process that yields fine, uniform grain structures and extremely high carbide content. These characteristics contribute to exceptional edge retention and corrosion resistance when heat-treated properly.

• CPM-S110V: Developed by Crucible Industries, CPM-S110V is known for its very good edge retention, fair toughness, and excellent corrosion resistance. It shines as one of the top-tier stainless knife steels used by several mainstream manufacturers.
• M398: Produced by Böhler-Uddeholm, M398 is formulated for incredibly high wear resistance. It also has excellent corrosion resistance and fair toughness, but it can be quite challenging to sharpen without diamond or CBN abrasives.

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2. Chemical Composition & Typical Performance

2A. CPM-S110V Overview

• Composition Highlights (approximate):

  • Carbon: ~2.8–3.0%
  • Chromium: ~14–16%
  • Vanadium: ~8.25–9.5%
  • Niobium: ~3–3.5%
  • Cobalt: ~2–3%
  • Molybdenum: ~2–3%

• Typical Hardness (HRC): Around 60–62 HRC in production knives, though some custom heat-treat protocols can achieve around 63–64 HRC.

  • Practical Implication: At ~60–62 HRC, CPM-S110V achieves a strong balance of wear resistance, corrosion resistance, and manageable toughness.

• Key Performance Characteristics:

  • Edge Retention: Very good. CPM-S110V holds an edge through extended cutting tasks.
  • Toughness: Fair. It’s not as tough as simpler carbon steels, but not overly brittle when properly heat-treated.
  • Corrosion Resistance: Excellent. High chromium and niobium content offer robust rust resistance in most environments.
  • Ease of Sharpening: Fair. Still challenging compared to lower-alloy steels; diamond or ceramic sharpening media is recommended.

2B. M398 Overview

• Composition Highlights (approximate):

  • Carbon: ~2.7%
  • Chromium: ~19–20%
  • Vanadium: ~7–7.5%
  • Tungsten: ~0.6–0.7%
  • Molybdenum: ~1%

• Typical Hardness (HRC): Around 61–63 HRC, with some specialized processes potentially reaching ~64 HRC.

  • Practical Implication: With its extremely high wear resistance, M398 benefits from elevated hardness but can be very difficult to sharpen.

• Key Performance Characteristics:

  • Edge Retention: Excellent. M398 is among the top steels for extended edge life, comparable to or exceeding other “wear-resistance-first” steels like Maxamet.
  • Toughness: Fair. Not intended for heavy impact or prying.
  • Corrosion Resistance: Excellent. The high chromium content (~20%) makes it highly rust-resistant.
  • Ease of Sharpening: Poor. Due to its extreme carbide content, sharpening is time-consuming without the proper abrasives.

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3. Detailed Alloy Element Effects

In both CPM-S110V and M398, several key elements determine overall blade properties:

• Carbon (C): Both have high carbon (>2.5%), contributing significantly to hardness and edge retention.
• Chromium (Cr): Ranging from ~14–16% in S110V and up to ~20% in M398, chromium imparts strong stainless properties.
• Vanadium (V): Vital for forming extremely hard vanadium carbides that enhance wear resistance and maintain edge stability.
• Molybdenum (Mo): Supports toughness and hardenability, present in both steels.
• Niobium (Nb) in S110V: Helps refine the microstructure, boosting wear resistance and corrosion resistance further.
• Tungsten (W) in M398: Contributes additional hardness and wear resistance when forming tungsten carbides.

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4. Heat-Treatment Nuances and Forging

Because of their high alloy content, both CPM-S110V and M398 require precise, advanced heat treatment:

• Heat-Treatment Complexity: They need carefully controlled high temperatures and soak times. A cryogenic treatment (sub-zero) is often used to convert retained austenite to martensite.
• Risk of Warping or Cracking: Their high carbide content makes them susceptible to thermal stress, so slow temperature changes and professional heat-treatment setups are ideal.
• Forging vs. Stock Removal: Due to their sensitivity and complexity, most makers opt for stock-removal methods (machining, grinding) rather than traditional forging.

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5. Patina Formation and Protective Coatings

• Patina Formation: With chromium levels above 14–15% (and up to 20% for M398), both are true stainless steels. They do not develop patinas under normal conditions.
• Protective Coatings: Generally unnecessary. Users may add coatings for aesthetic or tactical reasons, but both steels already resist corrosion effectively.

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6. Side-by-Side Comparison in Real-World Applications

Attribute	CPM-S110V	M398
Corrosion Resistance	Excellent	Excellent
Toughness	Fair	Fair
Edge Retention	Very Good	Excellent
Ease of Sharpening	Fair	Poor
Typical HRC Range	~60–62 (up to 64 custom)	~61–63 (up to 64 custom)
Ideal Uses	EDC, General Cutting	Extended Slicing, Hard-Use

Practical Application Notes

• Bushcraft: Both are not the top choice for repeated impact or batoning. However, if your bushcraft style relies more on slicing and fine carving, either steel offers excellent wear resistance.
• EDC (Everyday Carry): CPM-S110V is a top pick for users wanting extended edge life yet a slightly easier sharpening experience. M398 may be appealing if minimizing sharpening intervals is your priority, but be ready for harder re-sharpening.
• Kitchen Use: Both handle corrosive environments (water, food acids) well. M398’s extreme edge retention excels at repeated slicing, but sharpening at home can be difficult without diamond equipment. S110V is more manageable.
• Survival or Tactical: If you must sharpen in the field, CPM-S110V may be more practical. Both resist rust and handle general cutting tasks well.
• Ease of Sharpening vs. Wear Resistance: M398 delivers industry-leading wear resistance but demands specialized tools and patience during sharpening.

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7. Ideal Uses and Why to Pick One Over the Other

CPM-S110V

• Ideal For: Users seeking a mix of top-tier edge retention, excellent corrosion resistance, and relatively more forgiving sharpening (compared to M398).
• Why Choose It: Brands like Spyderco and Benchmade (in limited runs) use CPM-S110V, making it more widely available. If you value a balance of performance and somewhat more accessible maintenance, S110V hits the sweet spot.

M398

• Ideal For: Enthusiasts needing the absolute highest wear resistance and who have no issue investing in diamond or CBN-based sharpening.
• Why Choose It: For those who want minimal re-sharpening intervals and don’t mind the challenge when the time finally comes. Typically found in custom or semi-custom knives.

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8. Cost, Availability, and Maintenance

• Cost: Both steels are premium, but CPM-S110V may be slightly more common and competitively priced. M398 often appears in niche, high-end custom builds, contributing to higher pricing.
• Availability: CPM-S110V is more frequently seen in production knives by major brands. M398 is rarer, appealing mainly to connoisseurs and custom knife collectors.
• Maintenance: A simple wipe-down and occasional oiling is generally sufficient. Sharpening is the biggest maintenance factor: diamond or ceramic stones are recommended for both steels.

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9. Pros and Cons

CPM-S110V

• Pros:

  1. Excellent corrosion resistance
  2. Very good edge retention
  3. Fair ease of sharpening (relative to M398 and similar super steels)
  4. More widely available in production knives

• Cons:

  1. Not as tough as simpler, lower-alloy steels (e.g., 3V, 52100)
  2. Still requires diamond/ceramic stones for best sharpening results

M398

• Pros:

  1. Extremely high wear resistance, leading to excellent edge retention
  2. Superb corrosion resistance (very high chromium)
  3. Performs exceptionally in extended cutting tasks

• Cons:

  1. Poor ease of sharpening; highly wear-resistant carbides
  2. Fair toughness; not meant for heavy impact
  3. Less common availability and typically higher cost

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10. Summary of Key Takeaways

1. Both CPM-S110V and M398 offer top-tier stainless properties with high carbide content, resulting in excellent corrosion resistance.
2. M398 has the edge in ultimate wear resistance, making it hold its sharpness longer but also more difficult to resharpen.
3. CPM-S110V is still highly wear-resistant yet slightly more approachable when it’s time to sharpen.
4. Neither steel prioritizes impact toughness, so for heavy batoning or prying tasks, consider steels like 3V or 4V.
5. Production hardness levels typically sit around 60–62 HRC for S110V and 61–63 HRC for M398, with potential to go higher under custom treatments.

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11. Recommendations Based on Different User Needs

• Best for Durability + Wear Resistance: CPM-S110V strikes a more user-friendly balance among edge retention, corrosion resistance, and sharpening difficulty.
• Best for Extreme Edge Retention: M398 stands out for those who want minimal edge touch-ups — if you’re equipped to handle its difficult sharpening.
• Best Value & Availability: CPM-S110V is far more common in major production models, making it easier to purchase at a competitive price.
• For Hardcore Enthusiasts: M398 is perfect for those skilled in advanced sharpening or who don’t mind professional sharpening services.

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Conclusion

Choosing between CPM-S110V and M398 ultimately hinges on your needs and willingness to tackle the challenges of sharpening. If you prefer top-tier performance with a more attainable maintenance schedule, CPM-S110V is a standout choice. If the absolute peak of wear resistance is your dream — and you own diamond stones or have a trusted sharpening service — M398 delivers phenomenal edge longevity.

Either way, you’ll be holding a premium steel forged by modern metallurgical science. For EDC, kitchen, or specialized uses, both steels far exceed the capabilities of more conventional blade materials, offering long-lasting edges and robust corrosion resistance. Consider your sharpening setup, budget, and intended usage, and pick the super steel that best aligns with your style. Whichever you choose, your knife will exemplify the cutting edge of steel technology.