Knife steel guide

This blog will discuss the differences among S30V, S35VN, and S90V. The reason for choosing steel. 

Stepping into the world of high-end pocket knives can feel like walking into a metallurgy convention. Among the jumble of numbers and acronyms, three names consistently rise to the top: CPM-S30V, CPM-S35VN, and CPM-S90V. These are the titans of the "super steel" category, and the debate over which is "best" has been raging on knife forums for years.

As a knife steel specialist, I’m here to cut through the noise. These three aren't just random grades; they represent a deliberate evolution in the balance of properties for real-world use. Let’s break down the trio, focusing on performance and pricing.

S30V vs. S35VN: The Refined Siblings

Think of S30V and S35VN as brothers. The older one, CPM-S30V, was a revolutionary leap. Introduced by Crucible Industries with input from legendary maker Chris Reeve, it was one of the first steels designed specifically for knives. It set the gold standard by offering a previously unheard-of balance: excellent edge retention and great corrosion resistance in a stainless, powder-metallurgy package. It became so widely used that some enthusiasts now call it "boring," but as one industry expert noted, it's "a victim of its own success. It’s ubiquitous because it’s an excellent steel for a pocket knife".

Enter CPM-S35VN. The goal wasn't a complete overhaul but a targeted refinement. By adding a small amount of niobium, the chemistry was tweaked to make the steel easier for manufacturers to work with while improving toughness by a claimed 15-20% over S30V, without sacrificing too much wear resistance. In real-world use, this means an S35VN blade is slightly less prone to micro-chipping, especially with a fine edge. Most users wouldn't be able to tell the difference in a blind test, but the upgrade is a metallurgical improvement that often gives S35VN a slight edge in the eyes of experienced sharpeners.

• S30V Key Stats: Rate around 7/10 for edge retention and corrosion resistance, and 3/10 for ease of sharpening.

• S35VN Key Stats: Rate around 5/10 for edge retention, 7/10 for corrosion resistance, and 5/10 for ease of sharpening.

S90V: The Edge Retention King

Now, meet the cousin that went to an Ivy League school and makes everyone feel a little inadequate. CPM-S90V sacrifices some balance to pursue a single ultimate metric: wear resistance. It has nearly triple the vanadium content of S30V, which forms incredibly hard vanadium carbides. The result is an edge that just doesn’t know when to quit. Process game all day, cut miles of cardboard, and an S90V knife will still bite. It also has improved corrosion resistance over its predecessors.

However, this specialization comes with trade-offs. First, sharpening. S90V is notoriously difficult to bring back to a screaming-sharp edge. You absolutely need high-quality diamond or CBN abrasives; standard whetstones will have you sweating all afternoon. Second, the high carbide volume can make S90V less tough and theoretically more vulnerable to chipping during hard lateral stress or impacts, like accidentally hitting bone at an angle. Some experienced users report no issues with careful use, but the steel demands respect.

• S90V Key Stats: Rates a top-tier 9/10 for edge retention but a frustrating 1/10 for ease of sharpening. Corrosion resistance is a 5/10.

Quick Spec Showdown

The Price of Performance

Based on my industry knowledge, pricing is directly correlated to the amount and type of alloying elements, as well as manufacturing difficulty.

1. S30V & S35VN: These are the sweet spots in value. Their raw material costs are fairly similar, yet the manufacturing costs differ significantly due to the higher carbon and vanadium content; S30V is much more expensive than S35VN to grind. Especially after the right heat treatment.  

2. S90V: This is a premium upgrade. The sky-high vanadium content makes the raw stock significantly more expensive and dramatically accelerates wear on the belts and tooling used to grind blades. That cost is passed directly to the consumer.

Final Verdict: Which One is for You?

• Choose CPM-S30V if: You want the ultimate benchmark for value and balance. It’s the steel that defined the category and still outperforms most of what's on the market.

• Choose CPM-S35VN if: You appreciate a refined version of the classic. It’s for a general EDC user who wants slightly better peace of mind regarding edge stability without paying a huge premium. 

• Choose CPM-S90V if: You are a performance maximalist—an edge-holding fanatic who owns a set of diamond stones and genuinely enjoys a sharpening challenge. It’s a specialized tool for those who detest touching up an edge in the field.

The truth is, any of these steels, with a proper heat treatment from a reputable maker, will serve you brilliantly. It ultimately comes down to a personal choice between an all-around balanced performer and a specialized champion of longevity. 

As makers, we chose the S30V and S90V for the folding knives not only to honor the legend but also for edge retention, which we consider the most important feature for a pocket knife, even if it costs more. In this size, the knife should hold its edge long enough for all the tasks it goes through daily, while leaving the toughness and easy sharpening to bigger knives, like fixed blades, for heavier work. Just like the difference between a knife and an axe.