When it comes to high-performance knife steels, two names often stand out: Elmax and S35VN. Both of these steels are renowned for their exceptional qualities, making them popular choices among knife enthusiasts, manufacturers, and custom makers. While both are categorized as premium stainless steels, they differ in terms of chemical composition, performance characteristics, and manufacturing processes.
In this article, we will dive deep into the scientific data behind these two steels. We’ll compare measurable properties such as chemical composition, edge retention, toughness, hardness, and corrosion resistance. Additionally, we’ll analyze their heat treatment requirements, manufacturing processes, and real-world performance to help you decide which steel is best suited for your needs.
Composition Analysis
The chemical composition of a steel directly influences its properties such as hardness, toughness, corrosion resistance, and wear resistance. Let’s start by comparing the chemical makeup of Elmax and S35VN.
| Element | Elmax | S35VN |
|---|---|---|
| Carbon (C) | 1.70% | 1.40% |
| Chromium (Cr) | 18.00% | 14.00% |
| Vanadium (V) | 3.00% | 3.00% |
| Molybdenum (Mo) | 1.00% | 2.00% |
| Silicon (Si) | 0.80% | 0.50% |
| Manganese (Mn) | 0.30% | 0.50% |
| Niobium (Nb) | – | 0.50% |
Explanation of Key Elements:
- Carbon (C): Higher carbon content increases hardness and wear resistance but can reduce toughness.
- Chromium (Cr): Chromium improves corrosion resistance. Elmax has a significantly higher chromium content than S35VN, contributing to its superior corrosion resistance.
- Vanadium (V): Both steels contain vanadium, which forms hard carbides that improve wear resistance and edge retention.
- Molybdenum (Mo): Molybdenum enhances toughness and corrosion resistance, with S35VN containing more molybdenum than Elmax.
- Niobium (Nb): Unique to S35VN, niobium contributes to improved toughness without sacrificing wear resistance.
Performance Metrics
Edge Retention
Edge retention is a critical factor for knife users who need their blades to stay sharp through extended use without frequent sharpening.
- Elmax: In CATRA tests, Elmax ranks well in edge retention due to its high vanadium content and fine grain structure from the powder metallurgy process. It holds its edge approximately 7% longer than S35VN[1].
- S35VN: S35VN also performs well in edge retention but slightly lags behind Elmax due to its lower chromium content and reduced vanadium carbide volume compared to other super steels like S30V[3]. CATRA testing shows that S35VN achieves about 132% edge retention relative to baseline steels like 440C[4].
Toughness
Toughness is the ability of a steel to resist chipping or breaking under impact or stress.
- Elmax: Known for balancing hardness with toughness, Elmax scores moderately in toughness tests due to its high hardness levels (up to 62 HRC). However, it is not as tough as some other premium steels like CPM-3V or CPM-S35VN[1].
- S35VN: S35VN was specifically designed for improved toughness over its predecessor, S30V. It is about 15-20% tougher than S30V due to the addition of niobium carbides[3]. This makes it more resistant to chipping under heavy use.
Corrosion Resistance
Corrosion resistance is vital for knives used in wet or humid environments.
- Elmax: With an impressive chromium content of 18%, Elmax offers excellent corrosion resistance, rated at around 60-70% in salt spray tests[2][6]. This makes it suitable for outdoor applications where moisture exposure is common.
- S35VN: While still highly corrosion-resistant due to its chromium content (14%), S35VN falls slightly behind Elmax in this category, with a rating of about 7.8/10 in corrosion resistance tests[4].
Hardness Range
Hardness is measured on the Rockwell C scale (HRC), and it affects edge retention and wear resistance.
- Elmax: Typically hardened between 60-62 HRC, Elmax achieves high hardness without becoming overly brittle thanks to its fine grain structure from powder metallurgy[1][2].
- S35VN: S35VN can reach a hardness of up to 61 HRC, though it is often tempered slightly lower (~58-60 HRC) to optimize toughness[3][4].
Direct Comparison Table
Here’s a side-by-side comparison of key performance metrics:
| Property | Elmax | S35VN |
|---|---|---|
| Edge Retention | ~7% longer than S35VN[1] | Slightly lower (~132%) compared to baseline [4] |
| Toughness | Moderate | ~15-20% tougher than S30V [3] |
| Corrosion Resistance | Excellent (~60%) [2] | Good (~7.8/10)[4] |
| Maximum Hardness | 60-62 HRC [1] | 58-61 HRC [3] |
| Cost Factor | Higher [6] | Slightly lower [6] |
Heat Treatment Considerations
Heat treatment plays a crucial role in maximizing the performance characteristics of any steel.
Elmax Heat Treatment
Elmax requires precise heat treatment parameters to achieve optimal results:
- Austenitizing Temperature: The recommended range is between 1080°C (1976°F) and 1150°C (2100°F) depending on the desired hardness[7].
- Tempering Temperature: Tempering should be done at around 200°C (390°F) or up to 250°C (480°F) for optimal properties like high hardness (~60 HRC) while maintaining toughness[7].
- Cryogenic Treatment: For maximum dimensional stability and reduced retained austenite, cryogenic treatment at temperatures as low as -196°C (-320°F) is recommended after quenching[7].
S35VN Heat Treatment
S35VN has more forgiving heat treatment requirements:
- Austenitizing Temperature: The ideal range is between 1925°F (1052°C) and up to 2000°F (1095°C) depending on the desired balance between hardness and toughness[8].
- Tempering Temperature: Typically tempered at around 1000°F (540°C) for two cycles of two hours each[8].
- Cryogenic Treatment: While not always necessary, cryogenic treatment can be used after quenching to improve hardness by reducing retained austenite[8].
Real-World Performance
Edge Stability
Both steels offer good edge stability due to their fine grain structures from powder metallurgy processes:
- Elmax tends to maintain a sharp edge longer under heavy use but may be more prone to micro-chipping at higher hardness levels.
- S35VN offers better chip resistance due to its enhanced toughness profile.
Sharpening Behavior
Sharpening behavior is another critical factor for knife owners:
- Elmax can be more challenging to sharpen due to its higher vanadium carbide content but holds an edge longer once sharpened.
- S35VN sharpens more easily compared to Elmax but may require more frequent touch-ups during extended use[6].
Wear Patterns
Wear patterns depend heavily on the type of cutting tasks:
- Elmax excels in abrasive tasks like cutting rope or cardboard due to its wear-resistant carbides.
- S35VN performs well in tasks requiring impact resistance or lateral stress, such as batoning wood or chopping.
Manufacturing Considerations
Both steels are produced using powder metallurgy processes, which result in fine grain structures that enhance performance across several categories.
Production Costs
The production method significantly impacts cost:
- Elmax is generally more expensive due to its complex alloy composition and slightly more involved manufacturing process[6].
- S35VN is somewhat cheaper but still considered premium steel due to the Crucible Particle Metallurgy process used in its production[5][6].
Conclusion
Both Elmax and S35VN are excellent choices for high-performance knives, but they excel in different areas:
Best Use Cases:
- Choose Elmax if you prioritize edge retention and corrosion resistance. It’s ideal for outdoor knives exposed to harsh conditions or for users who need long-lasting sharpness with minimal maintenance.
- Opt for S35VN if you need toughness and ease of sharpening. It’s perfect for larger blades or tools that will experience heavy impact or lateral stress.
In summary:
- For outdoor survival knives or EDC blades that see regular wet conditions—go with Elmax.
- For tactical or combat knives where toughness is paramount—choose S35VN.
FAQs
- What makes Elmax more corrosion-resistant than S35VN?
- Elmax has higher chromium content (18%), which enhances its ability to resist rusting in wet environments.
- Is one steel easier to sharpen than the other?
- Yes, S35VN sharpens more easily compared to Elmax due to its lower vanadium carbide content.
- Can both steels be used for large blades?
- Yes, but S35VN may perform better in larger blades due to its superior toughness.
- Which steel holds an edge longer?
- Elmax holds an edge slightly longer than S35VN, especially during abrasive tasks like cutting rope or cardboard.
Citations:
[1] https://knifeknowitall.com/elmax-steel-composition-review/
[2] https://www.uddeholm.com/us/en-us/products/uddeholm-elmax-superclean/
[3] https://www.hudsontoolsteel.com/technical-data/steelCPMS35VN
[4] https://knifesteelnerds.com/2020/01/13/s35vn-steel-properties-and-how-to-heat-treat/
[5] http://zknives.com/knives/steels/cpm_s35vn.shtml
[6] https://nobliecustomknives.com/elmax-steel/
[7] https://www.tophamknifeco.com/how-to-heat-treat-bohler-elmax-for-best-results/
[8] https://www.tuofa-cncmachining.com/tuofa-blog/s35vn-steel.html
[9] https://knifesteelnerds.com/2021/10/19/knife-steels-rated-by-a-metallurgist-toughness-edge-retention-and-corrosion-resistance/
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