Steel matchup
CPM S45VN and CPM S35VN, compared on the five things that decide a blade: toughness, edge retention, corrosion, heat treat and how each one grinds.
A premium powder-metallurgy stainless steel from Crucible, built on S35VN with more chromium and nitrogen for stronger edge retention and corrosion resistance at only a small toughness cost.
A refined, well-balanced powder-metallurgy stainless steel from Crucible, offering dependable all-around performance across toughness, edge retention, and corrosion resistance.
Dimension by dimension
Each steel's own note, its score out of five, and what separates the two in that one column. The higher score in a row is marked in purple.
| Dimension | CPM S45VN | CPM S35VN | What separates them |
|---|---|---|---|
| Toughness | Only slightly less tough than S35VN despite the higher carbide load, and still an improvement over S30V once hardness is accounted for. | Noticeably tougher than its predecessor S30V, thanks to niobium carbides replacing some of the vanadium carbide load, one of the better toughness figures among premium powder-metallurgy stainless steels. | Essentially tied. Both share a very similar toughness profile, S45VN's added vanadium and niobium content boosts wear resistance without meaningfully sacrificing the toughness that made S35VN popular in the first place. |
| Edge retention | Rated around 143% CATRA edge retention versus 440C, matching S30V and beating S35VN, among the better edge-holding stainless steels in this class. | Strong, dependable edge retention, slightly below S30V's, but still well ahead of basic stainless steels like 420HC or AEB-L. | S45VN pulls ahead here. Its higher vanadium content forms more hard carbides, giving it a real, noticeable edge-retention advantage over S35VN in extended cutting tasks. |
| Corrosion resistance | The best corrosion resistance in the S-series thanks to 16% chromium and a nitrogen addition; noticeably better than S35VN in salt-air and marine testing. | Nearly identical to S30V and considered very good for a high-performance stainless, suitable for kitchen, marine, and everyday-carry use. | S45VN also has the edge, its higher chromium content pushes it into top-tier stainless corrosion resistance, while S35VN remains very good but a step behind. |
| Heat treat | Austenitize at 1950-2000 F (the higher end of this range has shown improved toughness), then quench to below 125 F. Unlike S35VN, S45VN is double tempered at a much higher 600 F for at least 2 hours per cycle, cooling to hand-warm between cycles. This combination typically lands in the 58-61 Rc range, trading a little peak hardness for S45VN's strong all-around balance of edge retention and corrosion resistance. | Preheat at 1550-1600 F, then austenitize around 1900-2025 F for 15-30 minutes. Plate quench, followed by a cryogenic treatment (liquid nitrogen, at least 30 minutes) for best properties. Double temper at 300-400 F for 2 hours per cycle: 300 F favors maximum hardness (60+ Rc), while 400 F trades some hardness for added toughness. This combination gives S35VN's well-rounded, dependable performance without any single weak point. | Similar heat-treat requirements and equipment needs; makers already set up to heat treat S35VN won't need to change their process meaningfully to work with S45VN. |
| Grinding | Grinds similarly to S35VN, moderate for a powder-metallurgy steel; expect faster belt wear than simple carbon or basic stainless steels. | Easier to grind than S30V, a deliberate improvement in the alloy design, but still a powder-metallurgy steel that wears belts faster than simple carbon or basic stainless steels. | Comparable, both are moderately demanding PM stainless steels that benefit from diamond or CBN abrasives for efficient sharpening, with S45VN's slightly higher carbide content making it marginally slower to grind. |
Best use
CPM S45VN
S45VN is the better pick when maximizing edge retention and corrosion resistance matters most, hard-use EDC or knives that will see wet or humid conditions regularly.
Open the CPM S45VN referenceCPM S35VN
S35VN remains an excellent, cost-effective choice with a long, well-proven history across nearly every knife category.
Open the CPM S35VN reference
The long answer
CPM S45VN was developed as Crucible’s follow-up to the widely popular CPM S35VN, and it’s often marketed as a straightforward upgrade. That’s mostly accurate, but the two steels aren’t identical, and the differences matter depending on what you’re building.
Keep comparing
Keep reading
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Same bench
Whichever steel wins, the grind is only as flat as the platen behind it. I machine the parts, hand-assemble, track and test Torus grinders in Sterling, Illinois.
Current dual-axis platform with a fiber-laser-cut 6061 chassis and single-knob tracking.
Current dual-axis platform with a steel chassis, more mass and less vibration.
Prior-design aluminum chassis, 90-degree tilt and 1.5-inch tooling arms.
One-man shop
Tell me what the blade is for and how you heat treat, and I will tell you which of these I would put on the bench — including when the answer is neither.
