S90v VS M390 Steel Knives: Which is the Sharpest Choice?

Steel is a revolutionary material that has changed the face of the earth and replaced almost all other materials for manufacturing, tool crating, and production. According to historians, steel was first invented in 1800 BC, 4000 years ago and found traced during an Anatolia excavation. But, the modern era of steelmaking was pioneered by Henry Bessermer in 1855, who introduced the most effective process for steelmaking at that time. Since then, steel is dominating the world in manufacture, production, and tool crafting. And knives aren’t left behind from this as well. After the industrialization of steel, this material has replaced all popular choices for knife crating. Some traditional knife crafting materials were flint (the earliest knife-crating material), cobalt, copper, obsidian, plastic, ceramics, etc. Knock makers choose steel over other materials because steels are easy to produce, durable, hard, and tough. It also has great strength, wear resistance, edge retention, corrosion resistance, and ease of sharpening over other materials. Steel has several grades and types, from premium to average grades. The S90V and M390 are the perfect examples of premium-grade steel. Those two are considered in the same class and share almost the same properties. S90V and M390 are the perfect choices for high-end knife crating due to their composition, structure, and properties. But one has to win the race. So, let’s find out which S90V vs M390 steel knives are the best.

Overview of S90V Steel

The S90V is a premium-grade martensitic stainless steel that belongs to the SxxV steel family made by American Company Crucible. This steel was first patented in 1996 and named CPM 420V. Later it got the name CPM S90V. It is high-end steel that is a popular choice for tool crafting, especially knives. Its chemical composition is responsible for its exceptional beneficial properties, which are:

Chemical Composition

  • Carbon (2.3%): Considered as high carbon steel with a high carbon content responsible for higher hardness and wears resistance and strength.
  • Chromium (14%): This amount of chromium makes the S90V steel stainless and is also responsible for toughness, tensile strength and extreme corrosion resistance.
  • Vanadium (9%): The steel has excellent wear resistance and toughness.
  • Molybdenum (1%): Increases hardness, strength, toughness, and machinability.
  • Silicon (0.5%): Improves corrosion resistance and strength.
  • Manganese (0.5%): Responsible for hardenability and wear resistance.
  • Tungsten (0.40%): Improves hardness, hardenability, toughness, and heat resistance.
  • Phosphorus (0.03%): For better machinability and hardness.
  • Sulfur (0.03%): Improves machinability.


The S90V steel is considered premium-grade steel for crafting high-end knives and other tools. And it’s a popular choice due to its hardness, which is 57-59 HRC on the Rockwell Hardness scale. But the hardness can be improved to 66HRC with heat treatment. Thus, this steel is exceptionally hard and possesses tremendous strength thanks to its high carbon and vanadium contents.


Despite being extremely hard, the S90V steel has decent toughness. Due to the 14% chromium and 9% vanadium, this steel possesses good toughness that can bear terrible pressure.

Wear Resistance

High carbon, vanadium, and other alloys make this steel super wear-resistant. And that’s why knives crafted with this steel won’t become a dull, chip, or break easily.

Edge Retention

The S90V steel has a great edge retention property. Due to its extreme hardness, it can form a sharp edge that will last long because of the wear resistance.

Corrosion Resistance

Any steel with over 11% chromium is stainless steel that resists corrosion and rust. And The S90V steel has 14% chromium with vanadium and other alloys, which makes it highly resistant to corrosion and rust.


On the other hand, Sharpening is not easy with the S90V steel. That’s because it’s extremely hard and super wear-resistant. Thus, sharpening stones hardly affect this steel.

Overview of M390 Steel Böhler-Uddeholm

The M390 is a premium-grade steel introduced and manufactured by Bohler-Uddeholm in the late 1980s with third-generation powder metallurgy technology. This steel’s key advantage is its high chromium and vanadium contents, along with other alloys responsible for its beneficial qualities, making it highly suitable for knife and other tool crafting. Its chemical composition and properties are:

Chemical Composition

  • Carbon (1.90%): Responsible for extreme hardness, edge retention, strength, and wear resistance.
  • Chromium (20%): This much chromium is the reason for M390 steel having extraordinary corrosion resistance, toughness, and tensile strength.
  • Molybdenum (1%): For better hardness and machinability.
  • Vanadium (4%): Improves corrosion resistance, wear resistance, and toughness.
  • Tungsten (0.60%): For better hardness and wear resistance.
  • Manganese (030%): For better hardness and brittleness.
  • Silicon (0.70%): Improves heat resistance and strength.


The M390 steel’s hardness is measured at 60-62 HRC on the Rockwell Hardness scale. This extreme hardness results from 1.90% carbons and 4% vanadium, and other alloys. This hardness gives the steel the extreme strength required for cutting knives.

Corrosion Resistance

Talking about corrosion resistance is the most exceptional advantage of this steel. Its high amount of chromium and vanadium contents, which are 20% and 4%, makes this steel super corrosion resistant and won’t be affected by corrosion and rust – making it highly suitable for knife crafting.

Wear Resistance

The M390 steel is well resistant to wear as well. Its carbon and vanadium contents make it resistant to wear. Therefore, it won’t break, crack, or chip and won’t be affected by the abrasion.

Edge Retention

The edge retention is also good in the M390 steel. Due to its hardness, carbon, vanadium, and other alloy contents can form a razor-sharp edge. And with wear resistance, the edge will last longer.


The toughness of the steel mostly depends on alloys, especially chromium. Since the M390 steel has a higher amount of chromium, this steel is super tough that can bear extreme pressure without breaking or cracking.


Sharpening may seem hard with this steel due to its great hardness and wear resistance. But this steel also contains 20% chromium, which makes it relatively softer, and that makes it easy to sharpen.

Comparison of S90V and M390 Knives

Both S90V and M390 steel knives are excellent and high-end, but let’s check which has better properties in a side-by-side comparison:


The S90V steel knives possess better hardness than the M390 steel knives. That’s because, in the Rockwell Hardness scale, S90V steel has a hardness of 57-59HRC that can be boosted to 66HRC. But the M390 has a hardness of 60-62HRC. The S90V has 2.3% carbon content, and M390 has 1.9%.


In terms of toughness, the M390 steel has better toughness than the S90V steel. The M390 steel has 20% chromium and 4% vanadium. On the other hand, S90V steel has 14% chromium and 9% vanadium. Thus, the high vanadium makes the M390 steel tougher than the S90V steel.

Corrosion Resistance

Again M390 Steel wins on this one too. That’s because the M390 steel has 20% chromium and high alloy contents, and the S90V has only 14% chromium, less than M390. And high chromium content makes the M390 better in corrosion resistance.

Edge retention

Both S90v and M390 steel is great at edge retention. But The S90V steel has better edge retention. That’s because the S90V steel has a better hardness, carbon content, and wear resistance. Therefore, the S90V steel can retain an edge better and hold it longer.

Ease of Sharpening

It is easy to sharpen the M390 steel compared to the S90V. That’s because the S90V is harder and has better wear resistance, thus making it harder to sharpen. But the M390 steel is comparatively low hardness and wear resistance, and the high chromium makes the M390 soft, so it’s easy to sharpen the M390 steel.

Can I Use a Knife Sharpener Under $100 to Sharpen S90v or M390 Steel Knives?

Finding the Best Knife Sharpener Under 100 dollars may not be suitable for sharpening S90v or M390 steel knives. These premium quality steels are known for their extreme hardness and high wear resistance. To ensure proper sharpening, it is recommended to invest in a high-quality sharpening system specifically designed to handle such hard steels.

Pros and Cons of S90V and M390 Knives

Let’s take a look at the advantages and disadvantages of both S90V and M390 steel knives:

Pros and Cons of S90V Steel Knives

  • Hardness: A knife is necessary to be hard so that it can withstand pressure and have great strength for cutting and slicing. And S90V steel knives are extremely hard and rated 57-59HRC on the Rockwell hardness scale.
  • Corrosion Resistance: The S90V steel contains 14% chromium, making it a decent corrosion-resistant steel good for high-end knives.
  • Edge Retention: The S90V steel has greater edge retention due to its high carbon and alloy contents. And it can hold the edge for longer.
  • Sharpening: The S90V steel is extremely hard to sharpen due to extreme hardness and wear resistance. And sharpening stones has little effect on this steel.
  • Toughness: I am not saying the toughness is low with this steel. But compared to the M390 and other premium steels, the toughness is average on this steel.
  • Expensive: The S90V steel is very expensive, so knives crafted with this steel cost more and are limited.

Pros and Cons of M390 Steel Knives

  • Hardness: The hardness of the M390 steel is also great, which is 60-62HRC in the Rockwell hardness scale due to its 1.9% carbon and other alloy content.
  • Toughness: Despite being so hard, the M390 steel has great hardness. That’s because it’s 20% chromium and other alloy contents. It’s well-balanced with toughness and hardness.
  • Corrosion Resistance: The 20% chromium makes it super corrosion resistant, greater than other premium steels.
  • Edge Retention: The M390 steel can retain the edge easily due to its great amount of hardness and can also hold the razor-sharp edge for a long time.
  • Ease of Sharpening: Despite being so hard and wear-resistant, this steel is easy to sharpen because its high chromium content makes it softer, thus easy to sharpen.
  • Expensive: The M390 steel is a premium-grade material that is very expensive due to its complicated production process.
  • Limited Edition Knives: Since the M390 steel is very expensive and hard to produce, only limited edition knives and tools are produced with this steel.


What are S90V and M390 steels commonly used for? Both S90V and M390 steel is commonly used for knife crafting, whereas M390 steel is used for small knife crafting that is limited edition. Which steel has better edge retention, S90V or M390? The S90V steel has better edge retention compared to the M390 steel. That’s because the S90V has more carbon contents and higher hardness. Are S90V and M390 steels equally resistant to corrosion? No. The M390 steel has way more corrosion resistance than the S90V steel due to M390 steel’s 20% chromium content. How tough are knives made with S90V and M390 steels? Both S90V steel knives and M390 steel knives are very tough. But the M390 steel knives are tougher due to their high chromium and other alloy contents. Which steel is easier to sharpen, S90V or M390? The M390 steel is easier to sharpen. Its 20% chromium makes it softer and easy to sharpen. What is the recommended heat treatment for S90V and M390 steels? For S90V steel, the recommended heat treatment is 1000-1025°F or 540-550°C. And for M390 steel, the recommended heat treatment is 1100°C – 1180°C. Are there any notable differences in the maintenance requirements of S90V and M390 knives? Yes. It’s hard to sharpen the S90V steel. But with the M390 steel, the sharpening is easy. Can S90V and M390 steels be used for different types of knives, such as folding knives or fixed-blade knives? Yes, The S90V and M390 steel is perfect for different types of knives, such as fixed blades, folding knives, etc. Are there any specific advantages of S90V steel over M390 steel, or vice versa? Yes, there is. The S90V steel is harder than the M390 steel and has better edge retention. What are the typical uses or applications of knives made with S90V and M390 steels? Since both S90V and M390 are high-end steel stainless steel, thus, those steels are perfect for heavy-duty indoor and outdoor knives. How do S90V and M390 knives compare regarding durability and long-term performance? In terms of durability and long-term performance, the M390 steel performs well. That’s because it’s well-balanced with extreme hardness and toughness. Are there any cost differences between S90V and M390 knives? Both the S90V and M390 steel are very expensive. But the M390 steel costs more. Which steel is recommended for outdoor or survival use, S90V or M390? I will recommend the M390 steel. That’s because its super corrosion resistance is required for outdoor and survival knives. What reputable knife manufacturers offer knives with S90V or M390 steel blades? Benchmade and Spyderco are the two most popular knife makers using the S90V and M390 steel. Conclusion: Lastly, both S90V and M390 steel make the high-end knives that are best for heavy-duty tasks. Both of them offer almost the same qualities. In comparison, the S90V steel knives are extremely hard and have better edge retention with great strength. On the other hand, The M390 steel knives are super corrosion-resistant, tougher, and easy to sharpen. Thus, choose a knife according to your preference. But in my opinion, the M390 is a better choice for knives.

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