CPM S35VN Steel
When I research knife steels for KnifeUp Magazine, I always make it a deep dive and I look at no less than two dozen websites, articles, and product pages. One interesting thing that I’ve found while doing this research is the back and forth conversations that I see on some of the forums. It’s fun to see some people hailing certain steel as being the “endall”steel for making knives, while others sing the praises of a different material. With the recent run of boutique steels being brought to the market, blade enthusiasts have had no shortage of steels in which to rally around. With researching CPM S35VN, however, things were remarkably different. After pouring over page after page of forum posts, looking at several product sheets put out by the steel manufacturers themselves,
and reading reviews on knives made with S35VN, one general consensus was found. That consensus is that CPM S35VN is, in fact, considered to be the best stainless steel for knife making that is on the market today. I have seen more love for this metal than for any other I have had the opportunity to research. The forums are littered with links to tests, knife sellers, and YouTube videos, all touting this steel as the absolute best in the world for standard knives. This is not to say that S35VN is the best in every situation; we all know that there is no single “perfect” steel. But there is definitely a favorite steel, and S35VN is that steel.
Crucible Industries CPM S35VN was born in 2009 from a desire to make Crucible’s earlier super steel, CPM S30VN, even better. Crucible set out to increase the toughness and edge retention, while keeping corrosion resistance at a premium. They succeeded. S35VN is 15%20% tougher than S30VN without any loss of wear resistance. This is because they substituted niobium carbides for some of the vanadium carbides. All of this toughness nets a gain in chip resistance as well. The hardness of both the vanadium and the niobium carbides are harder and more effective than chromium carbides in providing wear resistance. The edge retention is also improved over conventional high chromium steels such as D2 and 440C. Because of Crucible’s CPM process, the resulting steel is very uniform and provides exceptional dimensional stability, grindability, and toughness over conventional melting processes. The industrial applications of CPM S35VN are specialty cutlery, feed screws, and dies. The longitudinal toughness is comparable to 420C and 154CM, however, the transverse toughness is five times higher. The resistance to chipping and breaking under side load stresses make this a perfect material for larger blades, such as machete’s and swords. The CATRA test measures wear resistance in relation to 440C, and CPM S35VN comes in at 145% better in that category. The chemical breakdown of CPM S35VN is as follows:
- Iron 79.1%
- Carbon 1.4%
- Chromium 14.0%
- Vanadium 3.0%
- Molybdenum 2.0%
- Niobium 0.5%
The Rockwell Hardness for S35VN is 58-61 HRC. With all of this toughness, hardness, and corrosion resistance, expect to pay a premium price for this “super steel.”
Favorites Using CPM S35VN Stainless Steel
Many large, and even small knife making shops have begun using this steel since its introduction nine years ago. Kizer Cutlery, Spyderco, Bark River, and Zero Tolerance are among many manufacturers that have utilized S35VN for their premium blades. The ubiquitous Bark River Bravo 1 carries the flag for this steel in a big way. Widely considered one of the best bushcraft/survival knives on the market today, the Bravo 1 excels in just about every category. The Bravo 1 was famously developed after members of the Marine Corps Force Recon purchased several knives from various manufacturers and tested them in realtime conditions. These Marines put the knives through torture tests and came up with a big winner. That knife was the Bark RIver Gamekeeper. The Marines contacted Bark RIver and asked them to make a new knife based on the Gamekeeper, though modified with a few changes. Bark River answered their call with the Bravo 1. This new knife has a 4.25inch drop point blade, convex ground, with a satin finish. The S35VN blade is a hefty .22inches thick. It features a ramp up thumb rest with jimping on the forward side for pressure on the plunge line while notching, and the rear is notched to strike a ferro rod.
There is no finger choil, but that was by design so that the cutting edge goes all the way to the handle slabs to assist in notching. A highly balanced knife, the Bravo 1 balances on the first finger thanks to a skeletonized tang. The black Micarta handle slabs are epoxied and bolted on, and the screw slots are ground off. On the rear of the tang, there is a lanyard hole for use in slippery conditions. A leather bushcraft style sheath is included. This knife is an absolute workhorse. It feels heavy in the hand, yet nimble enough to create the thinnest of feather sticks. The corrosion resistance of the CPM S35VN stainless steel makes the Bravo 1 as comfortable in the salty conditions of the Virginia coast as it is in the dry conditions of the high desert of Oregon.
Crucible Industries has created a masterpiece of 21st century science. These material engineers and metallurgist have, with this S35VN stainless steel, perfected the intricate dance different elements must undergo to achieve something truly remarkable. It’s easy to work with, easy to temper and heat treat, and easy to spend your money on. To the uninformed observer, S35VN may simply look like any other steel used on any other knife. To the United States Marine Corp Force Recon, however, this is the culmination of research, testing, and production of an implement just as important to them as the rifle they carry. Bushcrafters and survivalists depend on their blades as well, and this steel is designed with them in mind. If you’re ever asked which material you would use if you could only choose one blade for life, you could definitely do worse if you replied with, “Crucible CPM S35VN!”