CPM S90V Steel: Is it a Good Knife Steel?

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CPM S90V from Crucible is a super steel known for its ability to retain an edge for long even with frequent heavy-duty usage. It can be categorized with other super steels such as M390, Elmax, CPM 110V (its big brother), and CTS-204P. However, this sounds promotional if you have no idea of the chemical composition and properties of this steel. So, let’s explore them!

What is CPM S90V Steel?

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Made by the American brand Crucible, CPM S90V belongs to the family of premium steels. It is one of the steels in the SxxV series, a group of stainless steels formulated using the brand’s Particle Metallurgy (PM) process. C in CPM stands for Crucible.

The brand originally made this steel as tool steel and gave the name CPM 420V. This steel was used for making bearings, slitters, feed screws, valve components, gear pumps, cutters, and other tools for hard use.

Today, CPM S90V is a popular super steel used for designing high-end knives. However, it is expensive just like other super steels. Moreover, its grindability is not up to the mark, hence working with it is not that easy.

Popular brands such as Benchmade and Spyderco use this steel to make premium knives.

Chemical Composition

CPM S90V contains three main alloying elements in unusually high quantities, which are carbon, chromium, and vanadium. This blend makes it a type of premium steel. It is also stainless due to its high chromium content. Following are its constituents:

  • 2.3% Carbon: For higher hardness as well as greater ability than normal to keep corrosion and wear at bay
  • 14% Chromium: For excellent corrosion resistance, toughness, hardness, tensile strength, and edge retention
  • 9% Vanadium: For great resistance to wear, toughness, and strength
  • 1% Molybdenum: For better strength, hardness, toughness, and machinability
  • 0.5% Silicon: For better strength and resistance to corrosion
  • 0.5% Manganese: For better hardenability, forgeability, and resistance to wear
  • 0.40% Tungsten: For better hardenability, strength, and toughness along with hardness retention at high temperatures
  • 0.03% Phosphorus: For better hardness, machinability, and strength
  • 0.03% Sulfur: For better machinability

Steel Hardness

On the Rockwell scale of hardness, CPM S90V has a rating of 57-59 HRC. According to knifesteelnerds.com, depending on the heat treatment, this hardness level can go up to 66 HRC. This is truly a high level of hardness!

Even the range of 57-59 HRC is considered a great hardness level. This is generally the range of hardness level of steels used in making the modern EDC and other premium knives.

Properties

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  • Okay Toughness: Considering the hardness level of 57-59 HRC, this steel provides decent toughness. Yes, it is not the best, as with a high hardness level comes a low level of toughness. In terms of toughness, S90V falls behind steels such as S30V and S35VN, but you can compare it with that of D2. The toughness level of this steel is attributed to the PM process that is known for its uniform distribution of carbides. Vanadium carbide content, which is quite hard and significantly contributes to wear resistance but is unfavorable for toughness in traditionally produced steels. Nevertheless, in powder metallurgy steels, these carbides are small and they can contribute to toughness more than other types of carbides. Thus, S90V can withstand a fair bit of abuse without breaking.
  • Excellent Wear Resistance: This is one of the most commendable benefits of using an S90V knife. You can expect it to resist wear and abrasion in any circumstances. The credit goes to the high vanadium content from vanadium carbides. These super-hard carbides significantly contribute to extraordinary wear resistance. It enables the CPM S90V steel to endure lots of hard use without any signs of wear or tear. Even the shape remains intact for longer periods.
  • Moderate Corrosion Resistance: Due to high levels of carbon and chromium content, CPM S90V steel will not rust quickly. The 14% chromium content makes it stainless, and all stainless steels are resistant to corrosion. Another factor that ensures corrosion resistance is the presence of vanadium carbides. You can expect better corrosion resistance than its precursors but lower resistance than its more-molybdenum-rich upgrades such as S110V.
  • Superior Edge Retention: The high chromium and vanadium quantities in the chemical composition of S90V lead to superior wear resistance. This gives the steel the ability to retain a sharp edge for a very long time. This ability is superior to the standard stainless steels. It is better than the former PM stainless steels such as S30V. Whether you use its knife for light or heavy-duty jobs, the blade will not become dull easily.
  • Ease of Sharpening: Considering its high level of hardness, it is very hard to sharpen this steel. This steel has vanadium carbides that ensure an exceptionally high level of wear resistance. Most sharpening stones hardly have any impact on them. For sharpening such a kind of steel, it is essential to use a sharpener that is harder than the vanadium carbides, such as a diamond or CBN stone. You will need saintly patience for sharpening a CPM S90V steel blade. However, in return, you get a longer-lasting edge.

Comparison With Other Knife Steel Options

Let’s now compare CPM S90V with other steels in terms of different parameters such as corrosion and rust resistance, ease of sharpening, hardness, and toughness.

S90V vs S30V

CPM-S90V boasts a better edge retention ability than its younger brother S30V. But S30V easily surpasses S90V in terms of resistance to corrosion, toughness, and ease of sharpening.

CPM-S90V vs. CPM-S30V

S90V vs M390

Both are premium steels and have the same score when it comes to edge retention. However, M390 wins when it comes to ease of sharpening, resistance to corrosion, and toughness.

CPM-S90V vs. Bohler M390

S90V vs M4

CPM-M4 is also made using the PM process and is a premium stainless tool steel. It boasts the same unmatched edge retention ability as S90V but is tougher and easier to sharpen. However, S90V is more resistant to corrosion than M4.

CPM-S90V vs. CPM-M4

S90V vs S35VN

S90V overcomes S35VN in terms of edge retention. However, S35VN is admired for its better performance than S90V in all other areas such as toughness, ease of sharpening, and corrosion resistance. Furthermore, S35VN is more popular too.

CPM-S90V vs. CPM-S35VN

S90V vs Elmax

Elmax from Bohler is an alloy having high levels of vanadium, chromium, and molybdenum. Both these steels have the same performance level when it comes to edge retention and corrosion resistance. However, Elmax is tougher and easier to sharpen than CPM S90V.

CPM-S90V vs. ELMAX

Top 5 CPM S90V Knives

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So, is S90V Steel Good?

As a super steel option for premium knives, S90V provides exceptional resistance to wear, moderate resistance to corrosion, and great edge retention. It is also moderately tough enough to withstand a fair bit of abuse.