S30V Steel - History and Properties

Larrin

Larrin

Knifemaker / Craftsman / Service Provider
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New article on S30V, including information on its development. I was able to interview the lead development metallurgist, Dick Barber, who shared a lot of interesting information. I also compared its properties to other common knife steels and talked about the steel’s impact on the knife industry. https://knifesteelnerds.com/2020/04/13/s30v-steel-history-and-properties/
 
Thanks for another great article, Larrin.

I didn't see mention of the early and widespread reports of S30V chipping. A knife maker involved in the development of S30V told me that the early chipping was the result of quenches done too slowly. Is that your understanding?

My take has always been that S30V is a very good knife steel, but the heat treat is more critical than for other steels. There's less room for variances in the heat treat recipe. Is that your take?
 
Twindog said:
Thanks for another great article, Larrin.

I didn't see mention of the early and widespread reports of S30V chipping. A knife maker involved in the development of S30V told me that the early chipping was the result of quenches done too slowly. Is that your understanding?
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Chipping reports were mostly found on bladeforums. The reason why people reported them and why those reports went away would be speculation on my part. I would be surprised if quench speed among production knife companies has increased since then.
My take has always been that S30V is a very good knife steel, but the heat treat is more critical than for other steels. There's less room for variances in the heat treat recipe. Is that your take?
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I don't think that S30V is more difficult to heat treat than other knife steels. It's possible to heat treat any steel sub-optimally. Whenever I do a matrix of heat treatments and test toughness I find temperature ranges which are superior to others. Low alloy steels (ironically known for being "easy" to heat treat) have shown the most sensitivity to heat treatment.
 
Enjoyed reading of the history, properties and relationship to other knife steels.
Thanks very much for the info and the link!
 
Great article, Larrin.

Although S30V is nearly 20 years old, the fact that it's still considered a benchmark is a testament to just how good and well balanced of a steel it is. I didn't realize that S30V was designed for easy heat treatment in addition to the other good qualities it has. Ease of production definitely drives cost down for the manufacturer, which benefits the customer.

Yeah there are better steels out there, but they aren't as easy to produce and the consumer will pay a premium. I think there will be a place for S30V for the foreseeable future, I plan to buy more of it.
 
Larrin said:
Chipping reports were mostly found on bladeforums. The reason why people reported them and why those reports went away would be speculation on my part. I would be surprised if quench speed among production knife companies has increased since then.

I don't think that S30V is more difficult to heat treat than other knife steels. It's possible to heat treat any steel sub-optimally. Whenever I do a matrix of heat treatments and test toughness I find temperature ranges which are superior to others. Low alloy steels (ironically known for being "easy" to heat treat) have shown the most sensitivity to heat treatment.
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Chipping reports were widespread -- way to many to disregard. Lots of people experienced it. Many testers found it. All you have to do is Google it.

Supposedly, Crucible found that the chipping was caused by an excess of austenite, which was an artifact of too-slow quenching, but I haven't been able to find that report.

I know I had a couple S30V knives that chipped badly with light use; and I had others in that steel that did not chip.
 
Twindog said:
Chipping reports were widespread -- way to many to disregard. Lots of people experienced it. Many testers found it. All you have to do is Google it.

Supposedly, Crucible found that the chipping was caused by an excess of austenite, which was an artifact of too-slow quenching, but I haven't been able to find that report.

I know I had a couple S30V knives that chipped badly with light use; and I had others in that steel that did not chip.
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I remember D2 was also under fire for chipping too around that time.
 
A few years ago, Jerry Hossom, one of the experts who helped with the development of S30V, made this post on the history of S30V, its heat treating and the chipping issue. It's well worth a read:

[I added the boldface.]

Post No. 127 from:
https://www.bladeforums.com/threads/s30v-vs-m390-toughness.1225518/page-7

"These chats do seem to grow loud at times. Since I was alive when S30V happened and was one of the first evaluators of the steel, I'll share some history as I recall it. For starters, it certainly was developed as a knife steel - from the beginning. BUT, this was happening at a time when knifemakers and steel makers were just beginning to talk with each other in a meaningful way and some of the issues were still unknown to both parties. S30V is a very good knife steel, when it is properly made into a knife and that was a learning curve early on that some did well and some didn't. S30V is very touchy about its heat treatment. Most didn't know that then. Unless it gets a fast quench it just isn't the same steel. That's one reason some knife companies avoided it, because not all were equipped to do that, and those who did their own heat treating almost uniformly weren't. I and some of the others mentioned used Paul Bos or another heat treater who were properly equipped with atmospherically controlled ovens that could manage a fast quench. We didn't have any problems and were more than a little mystified by those who did. Once the fast quench issue was understood, most got on board and makers who did their own heat treat started using quench plates to get the fast quench. Suddenly, almost two years after it was introduced you began reading good things about the steel. Before that, S30V got bad press from about half the people who used knives made with the steel; others thought it was great, and it probably responsible for more shitstorms on these forums than any other steel ever made.

"It still had some problems though, and I'll confess there's not uniform agreement on the source of the problem. It could still be chippy at times, even with decent heat treating. I contend that problem is related to the finish applied to the final edge. A 220 grit finish which many use, creates an edge with very tiny little stress risers that CAN be a source of cracks, cracks leading to chips. Some had the problem, some didn't. I never saw the problem, but I finish my edges to 5 microns before stropping and polishing so likely wouldn't have. I suspect Crucible knew this, and was also listening to our complaints about how difficult S30V was to finish. S35VN, with the addition of Niobium is specifically designed to inhibit crack propagation. Some steels use Cobalt to achieve this, and that makes the edge less susceptible to the effects of those tiny little stress risers. S35VN is also easier to finish. Both steels are excellent, but probably not much fun for the average Joe to sharpen in the field. Thankfully the Vanadium obviates that need in most cases.

"Anyway, that's one knifemaker's memories of the history and experience with the steel. Others may certainly disagree."
 
Thank you for another great article. I like S30V. it is a good steel. I have never experienced chipping on any of my knives. I saw a knife with a poorly ground factory edge that had minor chips, but once it was resharpened that did not repeat. I have always thought that the reports of chipping over the last 15 to 20 years was from internet heroes repeating urban legend.

I am surprised at the catra results. I would have thought ZDP-189 to be farther up the ladder from S30V.
 
DocT said:
Thank you for another great article. I like S30V. it is a good steel. I have never experienced chipping on any of my knives. I saw a knife with a poorly ground factory edge that had minor chips, but once it was resharpened that did not repeat. I have always thought that the reports of chipping over the last 15 to 20 years was from internet heroes repeating urban legend.

I am surprised at the catra results. I would have thought ZDP-189 to be farther up the ladder from S30V.
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In my testing the ZDP-189 has ended up a bit higher. It just has so much chromium carbide.
 
I’m no steel nerd, or that knowledgeable but two of my favorite knives are s30v. And their steel properties are part of the reason why. They are well done and out perform any of the higher opinion steels I have, easily.
 
I've been delighted with my knives in S30V: Mini-Rukus and Buck Custom Shop 112. For some reason, the Mini-Rukus takes a finer edge, while the 112 responds best to a slightly coarser edge (DMT red).
 
Larrin said:
In my testing the ZDP-189 has ended up a bit higher. It just has so much chromium carbide.
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Your article on ZDP was very insightful, I think it (at least for me) ended a lot of the mystique surrounding it.

Would love to see an article on S110V or Maxamet!
 
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