CPM S45VN
CPM S45VN is Crucible’s next step up from S35VN, rebalancing the chemistry with more carbon, more chromium, and a nitrogen addition to push edge retention and corrosion resistance higher while giving up only a little toughness. The result is one of the best all-around premium stainless steels available, and a common choice for high-end EDC and outdoor knives.
Also known as: CPM S45VN, S45VN
Composition
| Carbon (C) | 1.48% |
| Chromium (Cr) | 16.00% |
| Vanadium (V) | 3.00% |
| Molybdenum (Mo) | 2.00% |
| Niobium (Nb) | 0.50% |
| Nitrogen (N) | 0.15% |
Properties
| Property | Rating | Notes |
|---|---|---|
| Toughness | ★★★★☆ | Only slightly less tough than S35VN despite the higher carbide load, and still an improvement over S30V once hardness is accounted for. |
| 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. |
| 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. |
| Machinability / Grinding | ★★★☆☆ | Grinds similarly to S35VN, moderate for a powder-metallurgy steel; expect faster belt wear than simple carbon or basic stainless steels. |
Heat Treatment
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.
Best Uses
A top pick for high-end EDC folders and outdoor or marine knives where corrosion resistance and edge retention both matter. Browse more entries in the Knife Steel Database, and see the Heat Treating Guide for the full stage-by-stage process.
Sources: Crucible Industries CPM S45VN datasheet; Larrin Thomas, Crucible S45VN Steel: Everything You Need to Know, Knife Steel Nerds.