S90V

Overview

CPM S90V is a specialist stainless steel for long edge life. Its high vanadium content and powder-metallurgy structure help it keep cutting abrasive material, but sharpening takes patience and hard use calls for restraint.

Choose S90V for cutting, not prying or chopping. It works best for owners who already have the abrasives and patience to maintain it.

Composition and History

CPM S90V includes:

• Carbon (2.3%) supports hardness and carbide formation.
• Chromium (14%) provides stainless properties and chromium carbides.
• Vanadium (9%) creates extremely hard carbides for wear resistance.
• Molybdenum (1%) supports hardenability and toughness.
• Manganese (0.4%) and silicon (0.4%) aid deoxidation and processing.

The CPM process keeps the carbide structure finer and more even than conventional melting could manage at this alloy level. The finer carbide distribution helps, though S90V still has limited toughness.

Performance Tradeoffs

Edge retention

S90V has excellent edge retention. In CATRA-style wear testing and real cardboard/rope use, it ranks near the top of practical stainless EDC options.

If your knife mostly slices abrasive material and you hate frequent sharpening, S90V is worth considering.

Toughness

The tradeoff for S90V’s wear resistance is reduced toughness. It is much less forgiving than 3V, CruWear, 14C28N, or MagnaCut.

This means S90V is not recommended for:

• Heavy chopping or batoning
• Prying or twisting applications
• Knives subjected to lateral loads or impacts
• Hard use in cold environments

S90V belongs in cutting tasks where the blade sees mostly straight edge-on loads.

Corrosion resistance

S90V contains 14% chromium, well above the 10.5% minimum for stainless classification, yet its corrosion resistance is middle of the road. Testing shows adequate performance for most knife use, but H1, LC200N, and M390 resist corrosion better.

Some of its chromium is tied up in carbides rather than remaining in solution for corrosion protection. In normal environments S90V is usually adequate, but marine or high-salt use may favor more corrosion-focused steels.

Ease of sharpening

S90V is difficult to sharpen. The high volume of hard vanadium carbides changes the tool requirement:

• Standard aluminum oxide stones struggle and wear quickly.
• Diamond or CBN abrasives are essentially required.
• Sharpening takes more time than it does with conventional steels.
• Consistent angles matter because correcting mistakes takes extra work.

Diamond or CBN is the practical baseline. If you do not own those abrasives, buy them before you buy an S90V knife.

Best Use Cases

S90V works best for:

• Users who make many cuts between sharpenings.
• Cardboard, rope, and other abrasive material.
• Premium EDC folders owned by people willing to maintain the steel.
• Cutting work that does not put lateral stress on the edge.

Practical Buying Guidance

Pros:

• Very high edge retention in a stainless steel
• Strong wear resistance for extended cutting
• Adequate corrosion resistance for normal use
• Fine grain structure from CPM process reduces brittleness

Cons:

• Difficult to sharpen without diamond/CBN stones
• Lower toughness limits hard-use applications
• Premium pricing
• Requires strong maker execution and quality control
• Not ideal for cold environments or impact loads

When not to choose S90V

• Not ideal for prying, twisting, or impact-heavy hard-use tasks where edge chipping risk is higher.
• Not a great choice if you want quick touch-ups on basic stones and low-effort sharpening.

Comparison context

• Compare with S110V to see where each steel wins in practical EDC use.
• Compare with M390 to see where each steel wins in practical EDC use.
• Compare with S45VN to see where each steel wins in practical EDC use.

Continue learning

• Read How to Choose Knife Steel by Use Case for a fast decision framework.
• Read CATRA Myths for Buyers to interpret edge-retention claims correctly.

Sources

• Knife Steel Nerds steel ratings reference
• Knife Steel Nerds metallurgy articles index