When it comes to high-performance knife steels, two names that stand out are S110V and M390. Both are premium steels known for their exceptional properties, but they cater to different needs depending on the application.
In this article, we will delve deep into the scientific data behind these steels, comparing their chemical composition, performance metrics such as edge retention, toughness, hardness, and corrosion resistance.
We will also explore their heat treatment requirements, manufacturing processes, and real-world performance characteristics. By the end of this comparison, you will have a clear understanding of which steel is better suited for your specific needs.
Composition Analysis
The chemical composition of steel plays a crucial role in determining its properties such as hardness, toughness, wear resistance, and corrosion resistance. Below is a comparison of the chemical makeup of S110V and M390:
| Element | S110V (%) | M390 (%) |
|---|---|---|
| Carbon (C) | 2.80 | 1.90 |
| Chromium (Cr) | 15.25 | 20.00 |
| Vanadium (V) | 9.00 | 4.00 |
| Molybdenum (Mo) | 2.25 | 1.00 |
| Cobalt (Co) | 2.50 | – |
| Tungsten (W) | – | 0.60 |
| Silicon (Si) | 0.50 | 0.70 |
| Manganese (Mn) | 0.50 | 0.30 |
Key Alloying Elements and Their Impact
- Carbon: Both steels have high carbon content, which contributes to their hardness and wear resistance.
- Chromium: M390 has significantly more chromium than S110V, which gives it superior corrosion resistance.
- Vanadium: S110V contains more vanadium than M390, resulting in harder vanadium carbides that improve wear resistance and edge retention.
- Molybdenum: Both steels contain molybdenum, which enhances toughness and corrosion resistance.
- Cobalt: Present in S110V but absent in M390, cobalt improves hot hardness and wear resistance.
Performance Metrics
Edge Retention (CATRA Test Results)
Edge retention is a critical factor for knife enthusiasts who require long-lasting sharpness during extended use.
- S110V: Known for its exceptional edge retention due to its high vanadium carbide content. In CATRA tests, S110V has been shown to cut approximately 750 mm of cardstock, placing it among the top performers for edge retention[5].
- M390: Also excels in edge retention but slightly less than S110V due to its lower vanadium content. CATRA tests show M390 cutting around 540 mm of cardstock, which is still impressive but not on par with S110V[8].
Toughness
Toughness measures a steel’s ability to resist chipping or breaking under impact.
- S110V: Due to its high carbide volume, S110V sacrifices some toughness for wear resistance. It has relatively low toughness compared to other high-end steels[7].
- M390: Offers a better balance between toughness and wear resistance due to its finer grain structure from powder metallurgy production. Its toughness is rated as good for a stainless steel with high wear resistance[4].
Corrosion Resistance
Corrosion resistance is essential for knives exposed to moisture or harsh environments.
- S110V: With 15% chromium content, S110V provides good corrosion resistance but not as high as M390[7].
- M390: With 20% chromium content, M390 excels in corrosion resistance, making it ideal for use in wet or humid environments[3][4].
Hardness Range (Rockwell C Scale)
Hardness affects both edge retention and ease of sharpening.
- S110V: Typically hardened to around 60-63 HRC, providing excellent wear resistance but making it more difficult to sharpen[7].
- M390: Can reach hardness levels between 60-65 HRC, offering a slightly harder edge than S110V when treated at the upper end of this range[10].
Heat Treatment Considerations
Both steels require precise heat treatment to achieve their optimal balance of hardness, toughness, and corrosion resistance.
S110V Heat Treatment
- Austenitizing Temperature: Typically between 2050°F – 2150°F (1121°C – 1177°C).
- Tempering Temperature: After quenching in oil or air, tempering is done at temperatures between 400°F – 600°F (204°C – 316°C) to achieve desired hardness levels.
- Challenges include achieving uniform heating due to the high vanadium carbide content that can lead to brittleness if not tempered correctly.
M390 Heat Treatment
- Austenitizing Temperature: Around 2150°F – 2200°F (1177°C – 1204°C).
- Tempering Temperature: Tempering typically occurs between 400°F – 500°F (204°C – 260°C).
- M390 benefits from cryogenic treatment after quenching to reduce retained austenite and improve hardness without sacrificing toughness[10].
Real-World Performance Characteristics
Edge Stability
Edge stability refers to how well the knife retains its sharpness without chipping or rolling during use.
- S110V: The high vanadium carbide content provides excellent edge stability for slicing tasks but can be prone to micro-chipping under heavy use or impact.
- M390: Offers better overall edge stability due to its finer grain structure and balanced carbide distribution[4].
Sharpening Behavior
Sharpening ease is an important factor for users who regularly maintain their knives.
- S110V: Extremely difficult to sharpen due to the large volume of hard vanadium carbides[7].
- M390: While still challenging due to its high hardness, M390 is generally easier to sharpen than S110V because of its finer grain structure[10].
Wear Patterns
Both steels exhibit excellent wear resistance but differ in how they wear down over time.
- S110V: Exhibits slow wear but can develop micro-chips along the edge under heavy use.
- M390: Wears more uniformly without significant chipping, making it better suited for tasks involving repeated cutting of abrasive materials like cardboard or rope[10].
Practical Applications
Both steels are used in high-end knives but cater to different types of users:
- S110V: Best suited for applications requiring extreme edge retention such as hunting knives or EDC knives used for slicing tasks.
- M390: A more versatile steel that balances edge retention with toughness and corrosion resistance, making it ideal for outdoor knives, kitchen knives, and EDC blades exposed to harsh environments[3][11].
Manufacturing Considerations
Production Method
Both steels are produced using powder metallurgy (PM), which allows for a more uniform distribution of carbides and results in finer grain structures compared to traditional steelmaking methods.
Cost Implications
Powder metallurgy is an expensive process due to the precision involved in alloying elements and controlling grain size:
- S110V tends to be more expensive due to its higher vanadium content and complex heat treatment requirements.
- M390, while also costly due to its PM production method, is generally more affordable than S110V because it strikes a better balance between performance and ease of manufacturing[9][10].
Direct Comparison Table
| Property | S110V | M390 |
|---|---|---|
| Edge Retention | Excellent | Very Good |
| Toughness | Moderate | Good |
| Corrosion Resistance | Good | Excellent |
| Maximum Hardness | ~63 HRC | ~65 HRC |
| Sharpening Difficulty | Very High | High |
| Cost Factor | Higher | Lower |
Conclusion
In conclusion:
- If you need extreme edge retention with less concern about sharpening difficulty or toughness, then S110V is an excellent choice.
- On the other hand, if you value a well-balanced steel that offers great edge retention along with superior corrosion resistance and easier sharpening characteristics, then M390 is likely the better option.
For knife enthusiasts looking for long-lasting performance in harsh environments or everyday carry scenarios where maintenance might be infrequent, M390 stands out as the more versatile option.
FAQs
- What makes S110V harder to sharpen than M390?
- The higher volume of vanadium carbides in S110V makes it more resistant to abrasion during sharpening.
- Which steel has better corrosion resistance?
- M390 has superior corrosion resistance due to its higher chromium content.
- Can both steels be used in kitchen knives?
- Yes, both can be used; however, M390’s corrosion resistance makes it more suitable for kitchen environments.
- Which steel holds an edge longer?
- S110V holds an edge longer due to its higher wear resistance from vanadium carbides.
- Are these steels suitable for beginners?
- Due to their difficulty in sharpening and heat treatment requirements, these steels are better suited for experienced users or professionals.
Citations:
[1] https://virgamet.com/offer/c100s-1-1274-ck101-c100-xc100-aisi-1095-carbon-spring-steel
[2] https://www.astmsteel.com/product/1-2210-steel/
[3] https://nobliecustomknives.com/m390-steel/
[4] https://www.bohlersteels.co.uk/en/products/m390-microclean/
[5] https://knifesteelnerds.com/2020/05/01/testing-the-edge-retention-of-48-knife-steels/
[6] https://bulletin.is.gliwice.pl/download/file/fid/5384
[7] https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by-a-metallurgist-toughness-edge-retention-and-corrosion-resistance/
[8] https://knifesteelnerds.com/2019/10/07/catra-tests-of-m390-knives/
[9] https://jswmi.in/write-up/process-of-steel-manufacturing/
[10] https://www.rootier.cn/news_detail/460.html
[11] https://www.shieldon.net/s35vn-vs-m390-steel-which-one-is-better/
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