How Good is CPM S90V Knife Steel?

Introduction

Crucible Industries CPM S90V Knife is tough stuff. This steel is well known for for its wear-resistance.  According to Crucible, S90V is used in plastic feedscrews, valve components, nozzles, slitters, cutters, gear pumps, pelletizing equipment, bearings, and other hard use parts. In the knifemaking world, S90V is legendary for its near perfect edge-retention.

It is close to impossible to dull a blade made of CPM S90V. That being said, you need the patience of a saint to sharpen it, however infrequent that may be. S90V is in the upper echelon of knifemaking “super steels”, as is evident by the hefty price tag that accompanies the knives to which it adorns. Spyderco, Benchmade, and HTM knives are just a few of the premium knifemakers using S90V.

In fact, Benchmade uses it almost exclusively. To get that wear resistance, it has a high carbon content. That should come as no surprise. But to reach the level of wear resistance that S90V has, it also has almost radical amounts of vanadium; almost three times as much as Elmax or S30V.

This leads to more vanadium carbides, freeing up the chromium to act as corrosion resistance. This is truly a “best of both worlds” story. The only other steel used in knifemaking that comes close to S90V is its cousin, CPM S110V. Along with this resistance to wear, the grind-ability of CPM S90V is poor.

The CPM process results in a finer, more uniform carbide distribution imparting improved toughness and grind-ability to high alloy steels. It also allows the design of more highly alloyed grades which cannot be produced by conventional steelmaking.

Overview

Typically, knife blades are compared to 440C and D2 tool steel. This is because these two metals have what are considered the benchmark of the properties that knife steels strive to attain. 440C is extremely corrosion resistant. D2 tool steel has very good wear resistance, making the edge retention terrific. What Crucible did with S90V is combine those characteristics into one material. This martensitic steel provides substantial improvements over both 440C and D2 in wear resistance, based on the fact that larger and harder vanadium carbides replace less hard chromium carbides. This has the added effect of providing stain and corrosion resistance because the chromium is freed up to enhance both.

The chemical composition of Crucible CPM S90V is as follows:

One aspect of knives using Crucible CPM S90V is the cost. This alloy is very hard on grinding belts and the machines that use them, transferring that cost to the end product. That being said, the almost cult-like following of those collectors wanting knives made with S90V has lead to a steady demand for those products. The market is saturated with many examples of knives utilizing this alloy. Though its wear resistance is legendary, it is not the hardest steel to hit the market. The Rockwell hardness of CPM S90V is 57-59 HRC. This allows the alloy to be used in larger knives and those used for chopping and batoning.

Favorites Using CPM S90V

There may be no better example using CPM S90V than Spyderco’s Proficient fixed blade in carbon fiber. Designed by Chris Claycomb of Bushcraft UK, this knife features a 5-inch drop point blade with a full flat grind and a plain edge. While typical bushcraft knives utilize a Scandi-type grind, the high wear resistance of CPM S90V allows a much thinner edge to be used, greatly increasing the cutting ability and precision control. The blade thickness is .14-inches, and being thinner than traditional bushcraft blades, the cutting dynamics are far superior with less friction. The Proficient features a full-tang design, increasing strength and giving the knife perfect balance. The highly contoured and polished solid carbon fiber handle scales are incredibly strong for their weight, and keep the overall heft down to a scant 6.22 ounces. The overall length of the Proficient is 8.75-inches, of which the handle makes up 4.75-inches. The cutting edge goes almost all the way to the bolster. The spine of the blade continues uninterrupted all the way to the covered pommel. Keeping the scales attached to the tang are two blind stainless steel bolts. A lined lanyard hole completes the handle and is useful when using the Proficient in wet or muddy conditions. Using this knife for long periods, as bushcrafting frequently requires, is a joy due to the ergonomics of the handle. There are no hot spots or jimping to rub fingers and hands raw. The long cutting edge allows you to choke up to the edge of the blade for delicate work such as making feather sticks or v-notches in a fire board. To round out this excellent knife, a traditional pouch-style leather sheath is included.

Conclusion

In doing research for this article, I was awed at the number of knife collectors and knife steel enthusiasts that freely said this was what they considered the best blade material for a knife. There were a few arguments, but that was the exception rather than the rule. It seems that quite a few smaller, one-man shops are using CPM S90V for two reasons. One being that more and more customers are requesting it, and two being that the knifemakers themselves are having success working with this alloy. That being said, you will be hard-pressed to find an example of a knife utilizing S90V for under $150. Most are in the $200 to $300 range, and I have seen some reaching $700. So what do you get for your money? You get a blade with a wear resistance that is almost supernatural, a corrosion resistance that flat out beats 440C, and edge retention that humbles D2 tool steel. As time goes on, be on the lookout for more and more manufacturers utilizing Crucible’s CPM S90V for their blades. As it becomes more widely available, the prices will, in turn, come down. So put this amazing “super steel” on your bucket list of knife collecting. You may just find yourself spoiled by its unique characteristics.