by Mike O’Brien
I recently listened to an episode of CBC’s venerable science show “Quirks and Quarks”, in which physicist and astrobiologist Dr. Sara Walker discussed her recent book “Life As No One Knows It: The Physics of Life’s Emergence”. The book explores the boundary between living and non-living chemistry, and how understanding these distinguishing criteria can help us to identify life beyond our own planet. One tidbit from the interview is that chemical compounds that require fewer than fifteen assembly steps can be explained without the presence of living processes, while those that require fifteen or more steps are improbable without the involvement of living processes. This got me thinking about the kinds of self-sustaining systems (chemical, organismal, cultural, etc) that allow for the emergence of substances and structures that would likely never arise otherwise. It just so happens that another “rule of fifteen” manifested in the industrial realm this year, in the likely disappearance of an improbable alloy following the commercial failure of its sole manufacturer. That alloy is CPM-15V, produced by Crucible Industries (“CPM” stands for “Crucible Powdered Metallurgy”), which filed for bankruptcy last December, after surviving a previous bankruptcy in 2009.
CPM-15V is a tool steel containing 15% vanadium and 3.4% carbon by weight (among other things). This is about one hundred times the amount of vanadium found in common “chrome-vanadium” steels, like the kind used for wrenches and other high-strength tools, and about six times the threshold of carbon defining a “high carbon” steel. The purpose for this incredibly high vanadium and carbon content is the creation of vanadium carbides, tiny crystals of vanadium and carbon that are much harder than the surrounding steel. In fact, they are so hard that steels with a high vanadium carbide content must be ground with diamond abrasives (or cubic boron nitride, which is slightly less hard but slightly more tough than diamond). These carbides are also much harder than just about any substance that would need to be shaped in an industrial application, making steels like CPM-15V an effective alternative to cemented carbide tooling (which use a deposited layer of tungsten carbide on top of a steel body) for things like milling tools and punching dies. Its relative toughness (compared to pure carbide) and machine-ability allows it to be milled into intricate and thin-sectioned tools would not be possible with cemented carbide, and that would have a shorter service life if made with lesser alloys.
Why do I, a writer who mostly concerns himself with environmental and animal ethics, know so much trivia about obscure tool steels? Because I also collect pocket knives, and absurdly over-performing steel is to collector knives as whale penis leather is to ultra-luxury cars (the animal ethicist in me implores you to boycott whale penis leather, which should not impact your life too much). One knife brand in particular is renown not only for using exotic steel, but for being the first and often only brand to use especially exotic alloys, spending considerable time and effort in figuring out exactly how to grind a blade out of something that was designed specifically to be abrasion-resistant. That brand is Spyderco, based in Colorado, which has also made blades out of Maxamet, an alloy that was developed to make the rollers that squash batches of extremely hard tool steel into sheets of usable thinness, and currently makes blades with CPM-Rex121, an alloy that contains so much carbide (about 1/3 by volume) it strains the technical definition of “steel”. These titanic clashes of properties (hard enough to squash the unsquashable, or cut the uncuttable, or grind the ungrindable) are no doubt a big part of the appeal of these super-steels to collectors; a chance to hold in one’s hand a pinnacle of technology, a better-than-the-rest piece of rare matter. At the manufacturing end, the Glesser family who runs Spyderco also relishes the challenge of forcing these metallurgical square pegs into consumer-usable round holes (or at least I hope that they do, otherwise they have chosen a rather miserable lot in life).
As an international operation (it uses manufacturers in Japan, Taiwan, China, and Italy, in addition to its own factory in Colorado), Spyderco uses Japanese, Austrian, Swedish, Chinese, and American steels. They also recently experimented with a Swiss-made ceramic compound (High Impact Ceramic, a yttrium-doped aluminum oxide) in their “Mule” series of standard-pattern test knives, provided to customers at the lowest possible cost in order to get user feedback. The materials for these test models are often chosen at the request of users in Spyderco’s official web forum, making for a rather unique company-customer feedback loop. (I assure the reader that I am not being paid to sing Spyderco’s praises, nor do I have any financial interest in the company. If anything I have a negative financial interest in them, as every time I interact with them it is to pay them eye-watering amounts of money for their products. Or at least that used to be the case; with I being Canadian and they being American, and the world being as it is in 2025, I have ceased buying their products for the foreseeable future. Which is a shame, because they keep getting better at making things that I want.)
Many of the steels used by Spyderco and other knife-makers (but particularly by Spyderco) were not designed for use in knives, and knife-makers generally represent too small a market to be catered to by the big players in steel manufacturing. Consequently, knife-makers (often beginning with especially adventurous custom makers, then followed by Spyderco) have to figure out how to process die steels, ball-bearing steels, milling tool steels and the like into a blade that is much thinner than the products for which the alloy was intended. This means that the heat treatment guides provided by manufacturers are often unsuitable for knives, and levels of toughness that are adequate for thicker industrial parts can fail in the thin geometry of a blade. In particular, “hot work” tool steels are tempered about twice as hot as a typical cutlery steel, in order to maintain their hardness at the red-hot temperatures produced by cutting steel at high speed. Such heat resistance is unnecessary for a pocket knife, and comes at the expense of maximum hardness, so following standard processing protocols would rob consumers of the peak performance they so deeply desire, but almost certainly don’t need. (Although, such “red hardness” does allow for the high-temperature application of protective coatings, which is useful since these grades of steel are not stainless, as adding stainless levels of chromium would be detrimental to other properties).
Ball bearing steels are particularly apt for pressing into blade-making duty, as their mix of hardness (to resist being squished out of round), toughness (to resist cracking under pressure) and corrosion resistance (to prevent rusting) match quite closely the criteria of a well-balanced knife steel. In fact, the major grades of ball-bearing steel over the last century or so (52100, 440C, 154CM) all became widely used as knife steels, especially the stainless grades from 440C onward. (A super-stainless grade of bearing steel developed for NASA, LC200N, was used by Spyderco in their “Salt” line of marine-grade corrosion-resistant models.)
Crucible is (was?) a company that defied the rule of steel-makers ignoring the needs of knife-makers. In 2001 it released S30V, a knife-focused super-steel developed in consultation with several high-end knife manufacturers. It is a modification of Crucible’s 154CM bearing steel, already popular for knives, improved by the addition of vanadium (and a corresponding increase in carbon) and by the use of powdered metallurgy processing. Powdered metallurgy is a process wherein molten steel is mixed to achieve an even distribution of ingredients, and is then sprayed out in aerosol droplets using a pressurized inert gas. These droplets, each containing an even mix of ingredients, solidify into a fine powder which is then hot-pressed just enough to sinter them into a solid ingot (sintering powdered metal is also how some 3D printers are able to make solid metal parts). The main benefit of powdered metallurgy is that it prevents the ingredients in the molten steel from aggregating into large carbides in the cooling steel. A conventionally cast version of a bearing steel like 154CM or a die steel like D2, which contain a modest amount of chromium carbides, will be significantly less tough and harder to finish than their powdered metallurgy versions. In contrast to this “nice to have” improvement with less exotic steels, the powdered process is a “need to have” for steels with a vanadium content exceeding 5% (or extremely high chromium content). Such clumping can be disastrous, creating failure points at which cracks can initiate, and making machining very difficult (imagine trying to work with concrete that has basketball-sized rocks unevenly distributed throughout). The powdered metallurgy process allowed vanadium content to be increased to 10%, resulting in the alloy CPM-10V. But above 10%, the vanadium began clumping together even in the liquid steel. In order to avoid clumping at 15% vanadium, Crucible had to heat the molten steel to nearly 1700℃, a temperature that other steel-makers like Bohler or Carpenter are unable to reach with their own powdered-metallurgy facilities (or perhaps they are just unwilling to inflict the additional wear and tear on their equipment, just to produce such a niche product).
CPM-15V had been considered for knives before, but was deemed not tough enough (and a huge pain to work with, though not as bad as Maxamet or CPM-Rex121). The recent (two years ago) release of Spyderco’s CPM-15V products resulted from a collaboration with Crucible and Shawn Houston of BBB Handmade, a custom knife-maker who specializes in using extremely wear resistant steels ground to very thin geometry. For example, some of his hand-made blades can chop through a standard framing nail with negligible damage, despite being thinner that two sheets of printer paper just behind the cutting edge. He achieves this by developing his own custom heat treatment protocols (and then testing them to the point of failure, and adjusting as necessary). With a planned design collaboration between Houston and Spyderco delayed by factory upgrades, Spyderco offered a special project where Houston would oversee the use of his own custom heat treatment on a special production run of CPM-15V blades in existing Spyderco models. This collaboration extended not just to Spyderco’s hardening and tempering of Crucible’s steel, but also had Houston overseeing Crucible’s production of the batch of steel to be used. By at least one measure of performance (the rope-cutting tests performed by Pete of Youtube’s “Cedric and Ada Outdoors” channel) the resulting blades out-cut Victorinox’s rather good standard stainless steel by a factor of ten, if not more (there are more variables at play than I want to get into right now).
If Crucible’s latest bankruptcy is indeed the end of 15V, this is quite a nice farewell for such an improbably extreme material. As with the internal combustion engine, a final burst of optimization comes just in time to herald its disappearance. Unlike the internal combustion engine, 15V’s optimization was not driven by a need to conform to regulations, or contend with economic competition from increasingly cheaper alternatives. This was a passion project that brought together heavy industry, consumer manufacturing and skilled crafting to attempt a “moon shot” of materials processing. It also came relatively quickly after the 2021 release of CPM-Magnacut steel, a generational leap forward from S30V designed by professional automotive metallurgist and (rather successful) recreational cutlery metallurgist Larrin Thomas. Dr Thomas, author of the blog “Knife Steel Nerds” and two books on the science and history of knife steel, recently partnered with Crucible to produce his latest alloy design, Magnamax, just as the news of Crucible’s bankruptcy was breaking. Unlike CPM-15V, with its uniquely demanding production parameters, these other alloys in Crucible’s portfolio can be reproduced by other companies under different trade names. (Another link in this industrial chain is the distributor, Niagara Specialty Metals, who purchases steel from companies like Crucible and rolls it down to usable sizes to sell on to knife-makers. Niagara will partner with other steel-makers to provide analogs of extinct Crucible products when possible).
Besides providing reading material for engineering nerds, steel-making is also a proxy for the industrial capacity of a country. It is especially important for defence, where whole categories of materiel are impossible without advanced metallurgy (aerospace, for instance). The failure of a leading-edge manufacturer like Crucible is therefore an ill omen for America’s long-lamented industrial base (although, Crucible had gone bankrupt before, and itself emerged in 1900 from the agglomeration of several regional companies that likely would have gone bankrupt themselves without joining together. Plus ça change…). China, on the other hand, continues to gain ground on America’s technological lead. Chinese knife brands have dominated the consumer market for the last decade, beating Western and Japanese brands on price and often (in the case of American and European budget brands) on quality. But the Chinese export knife industry has been hindered by having to import the top steel alloys, a sine qua non for many deep-pocketed knife collectors, from strategic competitors like Europe, Japan and the USA. Perhaps not for long, though. The standard Chinese budget steel, 8Cr13MoV, is an analogue of Japan’s AUS8, much respected in the 1980s and 1990s among Western consumers. More recently, Chinese makers have been using domestically produced analogues of Japanese VG10 and American 154CM, market leaders in the 1990s and 2000s and still fairly competitive today. Now, a long-time player in China’s export knife industry, Sanrenmu, has started marketing knives using a Chinese analogue of Crucible’s S35VN (an incremental improvement on S30V), the leading premium knife steel for Western consumers a scant few years ago. Presumably they are doing so with their own powdered metallurgy facilities, since it would be difficult to make this grade with conventional casting. If they are making this steel at a scale, quality and price that competes with Western producers, this represents a yet another advance for China’s industrial autonomy, at a time when the USA is making itself a particularly unattractive trading partner.
Will 15V rise again in China? Or be superseded? That seems more likely in my lifetime than the rehabilitation of America as a cradle of industrial innovation and long-term development, barring the exit of some high-performing states from the current federal mess. (Colorado, Spyderco’s home state, has a Democrat state government and was decisively won by Kamala Harris in the 2024 election, but is likely too far inland to feasibly join a California-Oregon-Washington alliance of seceding states. Crucible is located in New York, an even more Democrat-leaning state that has stronger secession prospects given the proximity of other politically aligned states, and Canada.) I don’t think it’s particularly off-colour to muse about the dissolution of the United States as a mere complicating factor in my acquisition of collectible steel trinkets. It’s certainly less unbecoming than ignoring the carbon footprint of these ultra-steels while patting myself on the back for eschewing stag handles and leather sheaths…
Sources:
www.knifesteelnerds.com (Dr Larrin Thomas)
forum.spyderco.com
www.youtube.com/@CedricAda (Cedric and Ada Outdoors)
www.youtube.com/@FearNoSteel (Shawn Houston)
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