Spyderco’s obsession with blade steel goes back almost 40 years to their very first production knives. At that time, most knife companies were content with the stainless steels that were readily available, most of which had carbon contents below .08 percent. The reason for this was that steels with higher carbon contents could not be fine blanked—a key manufacturing process that was instrumental in keeping production costs, and the ultimate retail prices of the knives of the era, affordable.
Although that was the accepted norm at the time, it wasn’t good enough for Spyderco founders Sal and Gail Glesser. After the late Al Mar helped them establish a relationship with their Japanese manufacturer, they quickly began looking for ways to “raise the bar” and create a superior product. One major step in that process was to upgrade the steel of their knives to Gingami-1, or GIN-1, also known (thanks to Sal) as G-2. Although still capable of being blanked, GIN-1 had .09 percent carbon and offered an incremental increase in hardness and edge retention over most competing blades at the time.
That episode was just the start of Spyderco’s relentless pursuit of high-performance blade steels. In Japan, it led to pushing the envelope with steels like MBS-26, ATS-55, VG-10, ZDP-189, HAP40, and the ultra-corrosion-resistant H-1. In the US, we were among the first to use powder metallurgy steels like CPM 440V and exotic alloys like Maxamet.
Although Spyderco continues to be an industry leader in the use of high-performance blade steels, we’ve always had one major limitation: the steels we had available to us were based on alloy formulas developed by someone else. To create a blade material that was truly their own, we needed the opportunity to be in on the “ground floor” of its development and have direct input into its alloy composition. While that sounds enticing, it’s a lot of work and a very substantial expense. Having a steel that is truly proprietary to us literally means being exclusively responsible for purchasing all of it that is produced. That’s a serious commitment.
Despite the challenges involved in a project of this magnitude, we were determined to create a blade steel all their own. Fortunately, Crucible Industries—long a premier supplier of high-performance steels to the cutlery industry—was receptive to the idea and agreed to work with us.
As a starting point for the new steel, Sal Glesser chose a time-tested Spyderco standard—VG-10 stainless steel. Produced by Takefu Special Steel Company, Limited, VG-10 has long been the trusted blade material for Spyderco’s Japanese-made knives. A cobalt-enriched stainless steel, it offers an outstanding combination of edge holding, toughness, corrosion resistance, and ease of sharpening, while remaining economical and easily machinable. As a workhorse blade steel for real knife users, VG-10 is tough to beat and is sure to remain a reliable Spyderco standard for many years to come.
Sal’s thought was to take the basic alloy composition of VG-10—a traditional ingot steel—and give it the benefit of Crucible’s particle metallurgy process. Rather than pouring the molten steel into an ingot and rolling it into its finished form, this state-of-the-art method involves rapidly cooling the molten steel with pressurized nitrogen to create a fine powder. This remarkable process “freezes” the alloys of the steel in their perfectly mixed state and helps prevent segregation—the separation of the alloys that inevitably occurs in ingot steel—and ensures an exceptionally fine, uniform grain structure. The powdered steel is then re-heated in high-pressure containers to create ingots that are rolled to toughen the steel and mill it into finished form.
In addition to incorporating the Crucible Particle Metallurgy (CPM) process, Sal also wanted to fine-tune the alloy mix of the new steel. Working closely with Crucible’s expert metallurgists during more than a year of exhaustive research, development, and testing, Spyderco carefully adjusted the recipe to achieve the optimal balance of qualities we desired. We christened the resulting steel CPM SPY27.
As previously noted, “CPM” refers to the Crucible Particle Metallurgy process, an acronym common to the formal names of all Crucible’s particle metallurgy steels. “SPY27” draws its name from “Spyderco” and the atomic number of cobalt, a key element in the steel’s formula that increases its strength and hardness while accentuating the positive properties of its other alloys.
SPY27 is a corrosion-resistant stainless steel containing a finely tuned recipe of carbon, chromium, niobium, manganese, molybdenum, nitrogen, silicon, and vanadium, all enhanced by the addition of cobalt.
Functionally, this sophisticated alloy mix yields a material that is somewhat similar to CPM S35VN, but with a higher proportion of niobium and nitrogen, a lower volume of carbon and vanadium, and the addition of 1.50 percent cobalt. This balance gives it hardness and corrosion resistance comparable to CPM S30V and CPM S35VN, and toughness on par with CPM S35VN. Its edge retention strikes a balance between that of VG-10 and CPM S35VN, while remaining easy to sharpen.
Spyderco is extremely proud of CPM SPY27 and excited to feature it in a number of their best-selling American-made products. We are confident that it offers an excellent balance of qualities that will be appreciated by those who use their knives seriously. We are also extremely grateful to their friends at Crucible Industries for working with us to create a steel that is distinctly Spyderco.
Originally appeared in the October 2020 Spyderco byte e-Newsletter.
