CPM-S35VN is, at the time of this publication, the single-most popular knife steel in existence. Take a look at BladeHQ, and you’ll find over 4,000 blades available in this alloy. D2 steel comes in second, with around 3,400 blades available.
Why is this powdered stainless alloy the most popular blade steel? Let’s find out.
Table of Contents
- S35VN Steel Composition
- How CPM-S35VN is Made
- Why S35VN (And CPM Steel) is Better
- S35VN vs. D2 Steel
- S35VN vs. M390
- S35VN vs. CPM-154
- S35VN vs. S30V
- The Best S35VN Knives
S35VN Steel Composition
- Carbon: 1.4%
- Chromium: 14%
- Vanadium: 3.0%
- Molybdenum: 2%
- Niobium: 0.5%
At a glance, this is a simple steel that contains just five elements. But this deceptively simple composition is the perfect recipe for a knife steel. Part of S35VN’s impressive performance is obtained through its manufacturing at the foundry: This is a CPM, or “Crucible Particle Metallurgy,” stainless steel.
How CPM-S35VN is Made
In typical manufacturing, steel is formed by melting and combining iron, carbon, and other elements in a furnace, then pouring the molten metal into castings to form solid ingots. But when these ingots cool and solidify, the carbides in the steel are allowed to form inconsistent shapes and segregate. They can clump together and create inconsistent a weak grain structure. This can create microscopic fissures, weak spots, and stress risers that reduce the steel’s strength and hardness.
CPM steels are further refined after initial casting to produce smaller, spherical, and more evenly distributed carbides. This is achieved by melting the steel a second time, blasting the liquid metal through high-pressure nozzles, and allowing the tiny molten particles to solidify in a nitrogen-filled room. The nitrogen gas prevents oxygen from oxidizing the steel as it cools in the air.
These tiny steel particles are then collected, heated to forging temperatures, and molded under immense pressure into final, ready-to-use ingots.
Why S35VN (And CPM Steel) is Better
This powdered metal manufacturing process creates a more even grain structure within S35VN, and all other CPM steels made this way. This process provides the steel with some key advantages:
Take a look at the photo comparing S35VN and a traditional ingot-formed steel, and you’ll see the CPM steel’s smaller and more rounded carbides. S35VN’s grain structure reduces stress risers, hard points within the steel that might cause fractures when bent or struck. The rounded edges and smaller sizes of the carbides allow the steel to flex more freely.
S35VN also derives improved strength thanks to its 0.5% niobium content. Niobium promotes a finer grain structure during CPM manufacturing, which further reduces stress risers and weak spots.
Normally, high strength and high hardness are inverse to each other: You can either have a hard, weak blade or a soft, strong blade. But the tighter, more uniform grain structure in S35VN allows it to yield both higher hardness and better strength. That’s also thanks to its high chromium, vanadium, and molybdenum content.
Chromium and vanadium produce the toughest carbides of all elements, while molybdenum promotes strength and weldability at forging temperatures to further improve the steel’s grain structure and strength. S35VN can be hardened up to 64 HRC, or as low as 57 HRC. On average, this steel is hardened to between 58 and 61 HRC.
This wide range of hardness ratings allows S35VN to be versatile. It can produce a harder, finer cutting edge or sacrifice some cutting performance in favor of an even stronger, more resilient blade.
High Edge Retention
S35VN steel resides in the “Goldilocks zone” when it comes to its carbon content: 1.4% is enough to drive plentiful carbide formation, but not so much as to introduce brittleness. Coupled with its 14% chromium and 3% vanadium, S35VN yields exceptional cutting performance.
My old Cold Steel Recon 1 Tanto has been utterly abused and survived an eight-year stint in the military. Its S35VN blade, even today, provides 82% edge retention — that’s after having been used as a pry tool, hammer, chisel, and camp knife. It is still, in my personal experience, the simultaneously toughest and best-cutting blade I own.
Its drop point-bladed companion, the Cold Steel AD-10, provided 90% edge retention when testing its S35VN blade, too.
S35VN perfectly balances strength and cutting power: It can cut and neatly slice all day, but it can also be used to strike, chop, pry, and stab with little to no risk of chipping, cracking, or suffering edge damage. Or, it can even be tempered to favor one task or the other.
High Corrosion Resistance
Because of its tight carbide formation and grain structure, S35VN is highly resistant to corrosion — and it’s likely to combat rust even better than conventional stainless steels. That’s because its even chromium dispersion ensures the surface of the CPM steel produces a uniform layer of chrome oxide. This is the protective layer that makes stainless steel corrosion-resistant.
In short, this CPM alloy does it all. Its tough, hard, long-wearing, sharp, and nearly rustproof. This is why S35VN is arguably the best knife steel.
But how does it stack up to the other most popular steels? Let’s compare.
S35VN vs. D2 Steel
S35VN is superior to D2 steel. On paper, these two alloys’ compositions aren’t terribly different: D2 has 1.4% to 1.6% carbon, 12% chromium, 0.7% to 1.2% molybdenum, 1.1% vanadium, and a few other carbides. Both steels can be tempered to approximately the same hardness (D2 varies between 57 and 61 HRC). S35VN only beat D2 in edge retention by about 4%.
But S35VN’s powdered metallurgy, and its higher chromium and vanadium content make it the better steel. It’s similar in strength to D2 but holds an edge longer, and it provides better corrosion resistance. D2’s only advantage is its cost. The average D2 blade will be priced about 50% less than the typical S35VN blade.
S35VN vs. M390
M390 provides significantly better edge retention than S35VN, but it’s brittle and more costly. M390 blades are noticeably weaker and harder to sharpen. M390 contains 1.9% carbon and is considered an ultra-high-carbon steel. It also contains 20% chromium, 4% vanadium, and 0.6% tungsten, making it one of the longest-wearing blade steels available today.
But all those carbides and cutting power come at a cost: An M390 blade will chip, crack, and suffer damage if not used lightly. The typical M390 knife costs between $250 and $400 — that’s two to four times more expensive than the average S35VN knife.
S35VN vs. CPM-154
CPM-154 has nearly equal edge retention, but it’s stronger than S35VN. Because of its lower carbon content (1.05%), carbide composition, and powdered metallurgy, CPM-154 contains fewer carbides than S35VN inside an equally tight, uniform grain structure. Both steels have similar average hardness ratings of 58 to 61 HRC.
With its higher molybdenum content (4%) promoting even greater consistency in forging, CPM-154 provides an incredibly resilient, flexible, and tough blade. For its strength, CPM-154 still affords good cutting power. S35VN only held an edge about 5% longer in testing.
S35VN vs. S30V
S30V and S35VN are nearly equally matched. They’re almost identical in composition (S30V contains 1.45% carbon, 14% chromium, 2% molybdenum, and 4% vanadium) and both are powdered steels. Because it contains 0.05% more carbon and 1% more vanadium, S30V provides slightly better edge retention. It beat S35VN in testing by 8.5%.
Because S30V contains more carbon and vanadium — and because it lacks niobium — it may be slightly weaker than S35VN. But the differences between these alloys are minimal, and either steel could theoretically beat the other through tempering and its obtained Rockwell hardness alone.
knives made from either alloy are priced similarly — around $100 to $200 — though S35VN’s popularity means you’re more likely to find “budget blades” or knives on sale for under $100.
The Best S35VN Knives
Speaking of costs, here are our top picks for quality S35VN knives that slice for the right price.
Cold Steel Recon 1 Tanto
The Cold Steel Recon 1 is one of the best knives ever made. Period. I know this from personal experience. There are few other knives that look this intimidating, with such a beastly blade, that cut as well as the Recon 1. It’s the epitome of what S35VN steel is made to be: Tough as nails, and great at slicing and chopping through just about anything short of actual diamond.
Zero Tolerance 0450CF
Every knife Zero Tolerance makes is a finely tuned cutting machine, so it makes sense one of their most popular models — the 0450 — is made from one of the most popular steels. This blacked out, unassuming drop point with a carbon frame is small enough for daily carry, but capable enough for big cuts and heavy tasks. Sure, it’s priced high (~$230 at publication). But the response from users speaks for itself.
Finding an S35VN knife for under $100 is tough. Finding a good S35VN for about $80 is even tougher, but CIVIVI delivers. The Micarta-scaled Pintail provides all the cutting performance this powdered steel can afford without the typical three-digit price tag. It’s a no-frills blade that provides everything you need — a comfy grip, simple frame lock, belt clip, and quality steel — and nothing more.
Spyderco Tenacious C112PBL
The timeless Tenacious remains one of Spyderco’s most iconic knives for a reason: They keep improving this already well-rounded wheel of a knife with all the newest steels. S35VN is no exception. The high flat grind and thin profile of the Tenacious favors S35VN’s high edge retention. Paired with a small, light profile that carries like a charm, the S35VN Tenacious is a dutiful daily slicer that’s perfect for the boat, warehouse, or 9-to-5 gig involving lots of cutting.