The blade steel keeps getting better, and we're genuinely not complaining

MagnaCut broke the old triangle. MagnaMax is the sequel nobody saw coming. Crucible went bankrupt, got acquired, and somehow the steel got cleaner. S45VN is quietly doing important work. SPY27 went mainstream. This is a good time to carry a knife.

The old triangle, toughness, edge retention, corrosion resistance, was treated for a long time as a hard constraint. You could optimize any two at the expense of the third, and the job of buying a knife was largely about deciding which trade-off you were comfortable making. High carbon steels were tough and held an edge but rusted. Stainless steels resisted corrosion but weren't as tough. Super steels pushed edge retention but were brittle or difficult to sharpen. The triangle held.

Then Larrin Thomas published his research, refined it publicly, and released MagnaCut. And the triangle, if it didn't break entirely, developed a significant exception.

MagnaCut and the moment things changed

The claim behind MagnaCut when it first appeared was essentially that it had managed to push toughness, edge retention, and corrosion resistance simultaneously rather than trading between them, that careful control of carbide composition had produced a steel that outperformed its price-equivalent stainless competitors in all three categories. This claim was met with the usual skepticism. It was also, on testing, largely correct.

What made MagnaCut significant wasn't just the performance numbers. It was what those numbers implied about how the old constraint had worked: the triangle had been real, but it had also been a function of where steel metallurgy was at a given moment, not a law of physics. The constraint was technological, not fundamental. Which meant it could be moved again.

Spyderco was the first major production brand to build identity around MagnaCut at scale, which is why you now see it across their lineup at price points that would have seemed optimistic a few years ago. Bradford followed with MagnaCut in the Guardian series. Other brands have adopted it. The steel went from theoretical interest to production reality faster than most people expected, and the price premium over mid-tier steels has compressed as volume has increased.

MagnaMax and the sequel nobody asked for

If MagnaCut was the moment, MagnaMax is Thomas following his own work to its logical next step. MagnaMax pushes the edge retention side of the equation harder, it's designed for applications where maximum wear resistance is the priority, and it accepts some trade-off in toughness to get there. Think of it as MagnaCut for people who sharpen infrequently and need an edge to survive months of serious use.

MagnaMax hasn't hit production knives at scale yet in the way MagnaCut has. It's been appearing in custom and semi-custom work, and a handful of production collaborations. It represents the direction rather than the current state, evidence that the researchers who moved the triangle once are continuing to move it, rather than treating MagnaCut as a destination.

Crucible, Erasteel, and the supply chain surprise

Crucible Industries, the American company that produced CPM steels including S30V, S35VN, S45VN, S90V, and others, filed for bankruptcy in 2023. This was a genuine disruption to the knife industry's supply chain, and the short-term response was predictable: uncertainty about continued production, price spikes on existing stock, concern about the future availability of steels that had defined the premium tier for decades.

What happened next was less predictable. Erasteel, a Swedish specialty steel company with its own powder metallurgy capabilities, acquired Crucible's assets and operations. Erasteel's production standards are, if anything, more consistent than what Crucible had been delivering in its later years, there are credible reports from knifemakers that CPM steels produced under Erasteel ownership have shown tighter heat treatment windows and more consistent performance than late-period Crucible production. The supply chain disruption resolved into something that may have improved the baseline quality of the steels it was supposed to threaten.

This is not a guarantee. Manufacturing acquisition outcomes are unpredictable and the knife industry's collective opinion on post-Erasteel CPM quality is still being formed from actual experience rather than expectation. But the early signs are better than the pessimistic scenario that seemed plausible when the bankruptcy was announced.

S45VN: doing quiet important work

S45VN is not exciting. It was announced as an evolution of S35VN, better edge retention, comparable toughness, improved corrosion resistance from vanadium carbide additions, and it has delivered on that brief without generating much editorial attention. It doesn't have a story the way MagnaCut does. It doesn't have a community of researchers behind it. It is simply a better S35VN that is being adopted steadily by the same brands that had adopted S35VN.

Kizer has been moving their premium line to S45VN. A number of other mid-tier brands have followed. The steel shows up in knives at the $100–200 price point and represents an incremental but real improvement over the steel it's replacing. The upgrade is not dramatic, but "not dramatic" and "not real" are different things. S45VN is quietly raising the floor on what a production folder in the $150 range delivers, which matters more over time than any single knife review can capture.

SPY27 and the mainstreaming of Spyderco's house steel

Spyderco developed SPY27 in collaboration with a Swedish steel producer as a proprietary stainless formula, tougher than CTS-XHP, better corrosion resistance than many comparable options, and specifically optimized for their heat treatment processes. For several years it appeared primarily in their mid-range and premium production, treated as a specialty option.

It has since spread. SPY27 now appears across a wide enough range of Spyderco models that it's no longer a marker of a premium tier, it's becoming their standard. The practical effect for buyers is that mid-priced Spyderco folders that would have shipped with VG-10 or 8Cr15MoV a few years ago are now shipping with a meaningfully better steel at no price increase. That's not nothing. That's the kind of market improvement that doesn't generate headlines but matters to the person carrying the knife.

What this actually means

The practical upshot of all of this is straightforward: the knife you buy today, at most price points, comes with better steel than the knife you would have bought at the same price point five years ago. The floor has risen. The ceiling has risen. The trade-offs that defined how you thought about blade steel choices are less constraining than they used to be.

This is not an argument to obsess over steel specifications, which remains a trap that produces anxiety without improving carry. It is an argument that the spec sheet, the one you used to read carefully, identify the steel tier, and make peace with the trade-offs, is less zero-sum than it was. The triangle is still there, but its corners have been pushed outward. The blade steel keeps getting better. We are genuinely not complaining.