When it comes to edge retention, S90v steel is far better than S30v steel as it can stay sharp for an incredible amount of time. However, S30v steel is much easier to sharpen, and some people find it to be a more practical option for a knife you intend to sharpen yourself.
If all you need is a knife that’s always sharp even if you don’t sharpen it regularly, then S90v steel is the way to go. I give it an 8 out of 10 in edge retention and durability and a 6 out of 10 in corrosion resistance.
However, that’s where the good stops and the bad begins. For starters, it isn’t easy to sharpen. That may not be an issue if you send your knives to the manufacturer to be sharpened, but you’ll definitely have a problem with it if you sharpen your knives yourself.
S90v steel is infused with both carbon and vanadium, which explains its impressive edge retention. It also explains its impeccable wear resistance. Vanadium makes the steel very hard and durable, and S90v steel is made up of 9% vanadium.
It is also very corrosion resistant. It qualifies as stainless steel because it contains 14% chromium, which is above the threshold (12%) needed to make a steel stainless.
The only problem (and I use the word problem loosely) I can say it has is its brittleness. Even though it is one of the hardest and most corrosion-resistant steels you’ll ever use, it’s still ridiculously brittle.
But if you think about it, even its tougher cousin, the S110v, is quite brittle, so I wouldn’t exactly call this tiny caveat a deal-breaker.
Even though its edge retention is inferior to that of S90v steel, this is steel a quality, high-end martensitic stainless steel. Its main advantage is that it is easy to sharpen (easier than S90v steel, at least) and is not too shabby when it comes to corrosion and wear resistance.
Like its tougher cousin, it contains carbon, vanadium, and chromium, so it is no pushover as far as toughness is concerned. In fact, most people find it to be quite balanced in terms of practicality because even though you won’t find it hard to sharpen, it is still as tough as nails.
S30v steel has more than decent edge retention. I attribute that to the inclusion of vanadium tungsten, manganese, and carbon in its forging. In fact, its high vanadium composition makes it far tougher than you might expect.
It’s not the toughest steel you’ll ever use, however. In fact, any steel that comes with decent hardness and good corrosion resistance is bound to suffer from a lack of toughness.
There’s no question that the S30v is a super steel. Even if it doesn’t hold an edge as well as S90v steel, proponents find it quite the practical option because it is fairly easy to sharpen and quite durable in general.
S90v Steel Vs. S30v Steel: Which is “Better”?
Edge Retention – S90v
Say what you want, but the S90v is still the better steel for holding an edge longer. If that’s your main priority—maybe you don’t walk around with a grinder—then you’ll find it much better than S30v steel.
Ease of Sharpening – S30v
The problem with the S90v steel is that it has low machinability and can take a long time to polish to a narrow edge, even if it does hold that edge incredibly well. For the practical knife user that’s always looking for the sharpest edge, the S30v is probably the better deal. Sure, it stays sharp long enough, but if you feel it dulling, a few minutes on the grinder can fix that.
Overall resilience – Tie
Both the S30v and S90v steels are exceptionally durable. They both score highly in terms of wear and corrosion resistance. However, they’re both very brittle steels, so you’re better off looking elsewhere if toughness is a strong requirement in your knife applications.
I should probably mention that both these steels are relatively tough to sharpen—S90v is just far more difficult. Even so, its proponents say that its sharpening issues can be fixed with some diamonds or a rough grit aluminum oxide utility stone.
As for the S30v steel, which is an excellent steel by all standards, it sharpens quite well, although it dulls much quicker than its (marginally) tougher cousin.
That said, get the S90v steel if you lack the patience (or time) to sharpen it yourself as you won’t need to do it very often, and the S30v steel if you prefer to sharpen your own knives.