S45VN vs M390 – Which Is A Better Knife Steel?

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At A Glance
S45VN, a martensitic stainless steel, is praised for its excellent toughness, corrosion resistance, edge retention, and relative ease of sharpening, while M390, a high-performance martensitic chromium steel, stands out for its superior hardness, extraordinary edge retention, and outstanding corrosion resistance. While both steels demonstrate impressive qualities, S45VN provides a balance between durability and ease of maintenance, making it a versatile choice for varied tasks. M390, though more brittle under intense use and harder to sharpen, is a preferable option for heavy-duty cutting due to its exceptional edge retention. The decision between S45VN and M390 ultimately hinges on the knife’s intended use and user preference.

Top Rated Knives

Blade steel is a fundamental aspect to contemplate when selecting a knife. Two notable blade steels often compared are S45VN and M390. In this write-up, we’ll be contrasting S45VN and M390 in aspects of their composition, hardness, toughness, corrosion resistance, edge retention, and ease of sharpening to ascertain which one surpasses the other for knife applications.

Navigating the terrain of knife-making materials can seem like a labyrinth for both the seasoned hobbyist and the neophyte.

To help clear up any confusion, this article will launch into a comprehensive comparison between two widely used knife steel types: Crucible Particle Metallurgy’s S45VN and Bohler-Uddeholm’s M390.

We’ll be investigating their chemical makeup and how they measure up in terms of their composition, hardness, toughness, corrosion resistance, edge retention, and ease of sharpening to determine which one is superior for knives.

Steel Background

Before plunging into the comparison, it’s crucial to comprehend what each steel type is and how they’re fabricated.

S45VN

This is a martensitic stainless steel, engineered as an improvement of S35VN, offering better edge retention and corrosion resistance. It’s recognized as a high-grade knife steel and is produced through Crucible Industries’ proprietary Crucible Particle Metallurgy (CPM) process, which results in very homogenous, high-quality steel.

M390

M390 is a high-performance martensitic chromium steel, very resistant to corrosion and wear, produced by Bohler-Uddeholm. With the addition of significant amounts of vanadium and molybdenum, it’s highly popular for high-end cutlery and frequently chosen by custom knife makers.

Steel Composition

The initial point of comparison is the chemical composition of each steel.

S45VN

• Carbon: 1.48%
• Chromium: 16.0%
• Molybdenum: 2.0%
• Vanadium: 3.0%
• Niobium: .15%
• Manganese: .5%
• Silicon: .4%
• Phosphorus: .03%
• Sulfur: .02%

M390

• Carbon: 1.9%
• Chromium: 20.0%
• Molybdenum: 1.0%
• Vanadium: 4.0%
• Tungsten: .6%
• Manganese: .3%
• Silicon: .7%

From the above composition, we can see that S45VN has marginally less Carbon but more Chromium, Molybdenum, and Vanadium than M390, contributing to its superior toughness, wear resistance, and corrosion resistance.

S45VN vs M390 – Complete Comparison

Hardness

Hardness is a vital attribute of knife steel as it directly impacts the edge retention and wear resistance.

S45VN has a Rockwell hardness (HRC) of 59-62, which is considered to be a perfect equilibrium between edge retention and toughness. It’s a resilient steel that can endure substantial use without chipping or breaking.

M390 has a Rockwell hardness (HRC) of 60-62, which makes it one of the hardest steels available. It is a very wear-resistant steel that can sustain an edge for an extended period, but it is also more brittle than S45VN and can chip or break under intensive use.

Toughness

Toughness refers to a steel’s capacity to resist chips and cracks under use.

S45VN is a tough steel that can endure rigorous use. It is a suitable choice for knives that will be subjected to challenging conditions. S45VN was precisely designed to enhance toughness. Its fine grain structure, resulting from the Crucible Particle Metallurgy process, gives it excellent resistance against chipping and breaking.

M390, while offering high hardness, is not as tough as S45VN, and may chip or crack under rigorous use.

Corrosion Resistance

The corrosion resistance of a steel determines its ability to resist rust and oxidation.

Being a stainless steel with 16% Chromium, S45VN offers excellent corrosion resistance. It is a suitable choice for knives that will be used in wet or humid conditions.

With 20% Chromium, M390 offers superb corrosion resistance, even surpassing S45VN. It is well-suited for tasks that involve frequent contact with water and other corrosive elements.

Ease of Sharpening

Ease of Sharpening refers to how simple the steel is to sharpen with conventional methods. It usually inversely correlates with edge retention and hardness.

S45VN is relatively easy to sharpen, but it can be more challenging to achieve a razor-sharp edge than some other steels. It is a good choice for knives that will be used for varied tasks.

M390, on the other hand, due to its high hardness and vanadium content, can be more difficult to sharpen than S45VN but offers outstanding edge retention.

Edge Retention

Edge retention pertains to how well a steel retains its edge during use. Harder steels maintain their edge better but are more challenging to sharpen.

S45VN has excellent edge retention, implying that it can maintain a sharp edge for a long time. This makes it a suitable choice for knives that will be used for slicing or cutting tasks.

M390 also has extraordinary edge retention, and while it may be more challenging to sharpen than S45VN, it’s an excellent choice for tasks that involve intensive cutting or chopping.

Price

As a premium knife steel, S45VN is pricier than many other options, its cost justified by its superior properties and the high-quality Crucible Particle Metallurgy process.

M390 is an even more costly option due to its exceptional edge retention and corrosion resistance properties. It’s an excellent choice for those willing to invest in a high-performance knife.

Conclusion

Both S45VN and M390 are exemplary blade steels, each with their distinctive strengths and weaknesses. S45VN is a tough, corrosion-resistant steel that can maintain a sharp edge for a long time and is relatively easy to sharpen. It is a suitable choice for knives that will be used for varied tasks. M390 is extremely wear-resistant steel that can sustain an edge for an extended period, though it may be more brittle than S45VN under intensive use. It is a suitable choice for knives that will be used for heavy-duty cutting or chopping tasks.

Ultimately, the choice between S45VN and M390 will depend on the intended use of the knife and individual preference. Both steels are excellent choices for knives and are favored by many knife makers and manufacturers. It is crucial to choose a reputable brand and manufacturer when purchasing a knife to ensure the full potential of the steel is realized.