CPM S90V knife steel

CPM S90V is what happens when a steel is designed around one question: how long can an edge keep cutting? Crucible’s answer packs 9% vanadium and 2.3% carbon into a powder-metallurgy stainless whose carbide volume out-wears essentially every mainstream blade steel — a working edge that survives cardboard, rope and abrasive media for absurd stretches. Everything else about S90V is the bill for that answer: it grinds slowly, sharpens grudgingly, chips before it bends, and costs accordingly. It is a specialist’s steel, and it is honest about it.

CPM S90V FAQ

Is CPM S90V a good knife steel?

For dedicated slicers whose owners prize edge retention above all — yes, nearly unmatched. The vanadium carbide population is so dense that in standardized cutting tests S90V lands at the top of the stainless chart, clearly above M390 and 20CV. It is the wrong steel for hard use, batoning, tips that pry, or owners who sharpen on basic stones.

How hard is S90V to sharpen?

This is the famous cost. Vanadium carbide is harder than aluminum-oxide and silicon-carbide abrasives — conventional stones polish the steel matrix around the carbides rather than cutting them, which is why S90V has a reputation for taking a “good enough” edge reluctantly. Diamond and CBN abrasives change the experience completely: with diamond plates, S90V sharpens slowly but normally. Sell or buy this steel with the diamond-stone conversation attached; details in our S90V grinding guide.

What hardness should S90V be run at?

Crucible’s data sheet aims at 56–59 HRC; its own test row is 58 HRC after a 2050°F austenitize and a double temper at 500°F. Crucible’s MagnaCut sheet tests S90V at 61–61.5 HRC without stating a cycle, so 56–61 HRC is the span Crucible’s paperwork covers; ask the maker for the actual hardness. The sheet’s cycle is a 2100–2150°F austenitize, a fast quench, a double temper at 400–750°F and an optional freeze between tempers — the same kiln-and-protocol discipline as every high-alloy PM stainless, covered in our heat treat guide. Stock removal only; nobody forges 9% vanadium on purpose.

Is S90V tough?

No — and it does not pretend. That carbide volume leaves modest impact toughness; thin edges chip on staples and bones that MagnaCut or 3V would shrug off. The design answer is geometry: S90V wants sensible edge angles (18-20 dps) and slicing duty, where its wear resistance gets to matter and its brittleness never comes up.

Is S90V stainless?

Yes, in practical terms. Around 14% chromium delivers real stain resistance for EDC and kitchen service — below M390’s margin and far below LC200N’s immunity, but rust is a non-issue with normal care.

S90V or M390?

S90V cuts longer; M390 does everything else a little better — tougher, easier to sharpen, easier to find, cheaper. For a pure cardboard-and-rope slicer, S90V earns its premium; for a general premium EDC, M390/20CV is the saner pick. Full breakdown: S90V vs M390.