S30V vs M390 Toughness?

Well said, I've heard awesome things about ed fowlers 51200 one day I would like to try that steel out.
Twindog said:
When S30V came out, it was touted as being a steel -- the first steel, I think -- that was developed for the knife industry. The "industry" is a key adjective because there were compromises made so that knives could be ground and heat treated in a high-production setting.

But that is a minor issue because what counts is how a steel performs. And what is sad is that we don't have good measures for comparing different steels because testing methods, production methods, final geometry, heat treating, etc., are all different. Which is tougher, M390 or S30V? We don't really know because 1) We don't have access to standardized testing methods, and 2) heat treats make a huge difference. Geometry makes a difference, too.

In another thread, I mentioned a section of an Ed Fowler book where he describes a very complicated process of heat treating 52100E, a steel used for ball bearings but one that works extremely well for knives. In a heat process that took many, many days, a blade was created that cut 300 percent better than ordinarily heat treated 52100 and was so tough that it was bent 180 degrees more than six times before it broke. So is 52100 tougher than 3V? Well that knife is tougher than any 3V knife I have. One of my 3V bowies that I got from a custom maker bent permanently under a test that Benchmade puts its S30V bush knife to. The problem I had wasn't with the steel, but with a crappy heat treat.

The comparographs floating around are super easy to read and very interesting, but they are notoriously inaccurate and contradictory. Crucible even has a comparograph out that shows S35VN is tougher than 3V. Few would agree.

So we go with what we know in trying to answer the question. Ankerson's tests of wear resistance are very well done, but testing for toughness is more challenging and more expensive. And heat treat is really key. I've had S30V from major makers that was chippy. And I have S30V now from those same makers that is not chippy at all. Chipping is an indication of poor toughness. I also have an S30V knife from Crusador Forge that is super heat treated and it acts like it is much tougher than ordinary S30V.

I think both these steels are excellent. And I'd guess that heat treat will determine which is tougher. But we almost never know anything about the heat treat of our knives.
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dogrunner said:
One more try (not sure it matters, but here it is anyway)...
The history is historically interesting. The data sheets are useful in narrowly defined way. Both are really BESIDE THE POINT, so there is no real value in a pissing contest.

The real point is that none of that answers the original question, or my question on another thread, or anyone else who wants to know what knife will have what properties (such as "toughness"). What WILL answer this sort of question is an actual test of actual knives subject to the forces that the tester is interested in testing (Nate the machinist's videos come to mind, 3V and Elmax compared - yes it was limited but at least it was real knives).

So all these pages and all this superfluous information and angst, and still no answer... :eek:
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The problem is that both S30V and M390 have been and are used in some knives that are designed for the harder use crowd and they both hold up in that type of use..

So the answer is still it depends....
 
A test would be great... for me its not a pissing contest
Its about the truth and the facts are clear for anyone to read...
dogrunner said:
One more try (not sure it matters, but here it is anyway)...
The history is historically interesting. The data sheets are useful in narrowly defined way. Both are really BESIDE THE POINT, so there is no real value in a pissing contest.

The real point is that none of that answers the original question, or my question on another thread, or anyone else who wants to know what knife will have what properties (such as "toughness"). What WILL answer this sort of question is an actual test of actual knives subject to the forces that the tester is interested in testing (Nate the machinist's videos come to mind, 3V and Elmax compared - yes it was limited but at least it was real knives).

So all these pages and all this superfluous information and angst, and still no answer... :eek:
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We agree on that it depends... so many variables as twin dog pointed who does the heat treat is a major factor.. so I'll second it depends.
Ankerson said:
The problem is that both S30V and M390 have been and are used in some knives that are designed for the harder use crowd and they both hold up in that type of use..

So the answer is still it depends....
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Ankerson said:
Yeah, we all read that too back in 2006.... ;)
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"We" didn't "all" read that in '06. Some of us are just reading it now, to further clarify our knowledge and understanding.

Just sayin'... there's no need to get snotty about it or discuss each other and ourselves more than the topic. :) Lighten up, Ank and shiny.

I have no comment on Mr. Fowler's claims about 52100 and his "extraordinary" HT protocol for it, other than to say: 52100 happens to make very good knives... even without top-secret magic and hype. The basic industry standards for getting it good and hard and tempering it back enough to improve toughness will get you very, very close to a dang good knife blade.

It's true that steel chemistry doesn't care if you make a die or a hammer or a filet knife out of it. The properties of the alloy remain the same.

It's also true that HT'ing the same steel can make a huge difference. Retained austenite can be a good thing in a 100# forming or cutting die; less RA and more tempered martensite is generally much better in a 3 oz fine-edged knife.
 
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james terrio said:
"We" didn't "all" read that in '06. Some of us are just reading it now, to further clarify our knowledge and understanding.

Just sayin'... there's no need to get snotty about it or discuss each other and ourselves more than the topic. :)

I have no comment on Mr. Fowler's claims about 52100 and his "extraordinary" HT protocol for it, other than to say: 52100 happens to make very good knives... even without top-secret magic and hype. The basic industry standards for getting it good and hard and tempering it back enough to improve toughness will get you very, very close to a dang good knife blade.

It's true that steel chemistry doesn't care if you make a die or a hammer or a filet knife out of it. The properties of the alloy remain the same.

It's also true that HT'ing the same steel can make a huge difference. Retained austenite can be a good thing in a 100# forming or cutting die; less RA and more tempered martensite is generally much better in a 3 oz fine-edged knife.
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I think Fowler has 52100 dialed in very well for what he wants it to do. :)
 
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.
 
Ankerson said:
I think Fowler has 52100 dialed in very well for what he wants it to do. :)
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Let's not even go there. That's a whole other topic, which can only result in a deadlock. I only brought it up as an example... and I already regret doing so :(

ETA I am very happy that Mr. Hossom has chimed in on this topic. Thank you!
 
james terrio said:
Let's not even go there. That's a whole other topic, which can only result in a deadlock. I only brought it up as an example... and I already regret doing so :(

ETA I am very happy that Mr. Hossom has chimed in on this topic. Thank you!
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I wasn't trying to start one... :D

And why I said he has it dialed in for what he wants it to do...
 
Jerry Hossom said:
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.
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Hi Jerry,

Thanks for ringing in. :thumbup:

Great information as always every time you post. :)

Jim
 
Let me share something Dick Barber told me back when this whole thing was getting started. My guess is that it's still true today.

"We [meaning steel makers] really don't know how these steels are going to perform in a knife edge and that's why we're talking with you knifemakers. You need to tell us."

I think the fact that Crucible listened to what we said back then is why S35VN happened, and they should be commended for having listened and responded to the concerns that were expressed.
 
Re: S30V...

Jerry Hossom said:
...it's probably responsible for more shitstorms on these forums than any other steel ever made...
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Heh... :D

I understand adding a lot more chromium for corrosion-resistance. {Let's reference AEB-L for an example of eutectoid but high chrome steel... tough and hard, but with most of the chrome "free" (not bound up in carbides)}. I also think I understand the reasoning behind a bit more moly and vanadium... better/more consistent HT response and more fine carbides.

But I do not understand why Crucible nearly doubled the carbon content, compared to 3V, if they wanted to keep the toughness. (my understanding is that moderate carbon content results in a different, more resilient structure, and that structure changes significantly if more carbon is in the mix). .8%C to 1.45%C is a huge, huge increase.
 
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james terrio said:
Re: S30V...



Heh... :D

I understand adding a lot more chromium for corrosion-resistance. {Let's reference AEB-L for an example of eutectoid but high chrome steel... tough and hard, but with most of the chrome "free" (not bound up in carbides)}. I also think I understand the reasoning behind a bit more moly and vanadium... better/more consistent HT response and more fine carbides.

But I do not understand why Crucible nearly doubled the carbon content, compared to 3V, if they wanted to keep the toughness. (my understanding is that moderate carbon content results in a different, more resilient structure, and that structure changes significantly if more carbon is in the mix). .8%C to 1.45%C is a huge, huge increase.
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They needed it to help convert the Chromium and other elements into carbides...
 
Thanks for chiming in james, I simmered down... your a knowledgeable man and i appreciate you taking the time write the words. I didn't think shape or sized changed properties.. and as most folks here know heat treat is the make or break for the steel.
james terrio said:
"We" didn't "all" read that in '06. Some of us are just reading it now, to further clarify our knowledge and understanding.

Just sayin'... there's no need to get snotty about it or discuss each other and ourselves more than the topic. :) Lighten up, Ank and shiny.

I have no comment on Mr. Fowler's claims about 52100 and his "extraordinary" HT protocol for it, other than to say: 52100 happens to make very good knives... even without top-secret magic and hype. The basic industry standards for getting it good and hard and tempering it back enough to improve toughness will get you very, very close to a dang good knife blade.

It's true that steel chemistry doesn't care if you make a die or a hammer or a filet knife out of it. The properties of the alloy remain the same.

It's also true that HT'ing the same steel can make a huge difference. Retained austenite can be a good thing in a 100# forming or cutting die; less RA and more tempered martensite is generally much better in a 3 oz fine-edged knife.
Click to expand...
 
Ha!! James, that is a sore subject with me, because I was clearly told at the time BY CRUCIBLE that S30V was to be a stainless CPM-3V, which clearly it never was. Ironically, I just learned why it wasn't from the current Chief Metallurgist at Crucible while at the Blade Show this year. It's too technically detailed to get into here, but the dirty little truth is that it was never intended to be a "stainless 3V"; it was intended to be a 3% CPM stainless, which got kicked up to 4% for some unknown reason. What it really is is a Vanadium laced 154CM made with the CPM process. Then, when they finally did get around to going after BG-42 with a CPM, they kept the Vanadium at 0.1% to control grain size instead of the 1.0% it is in BG-42, so CPM-154 happened and was in my judgement a disappointment. Not that CPM-154 isn't a great steel, it just could have been better. So they didn't ALWAYS listen. :)

Edited to add: They didn't need to convert the Chromium to carbides if they just used less Chromium AND less Carbon. That is the enigma about what they were thinking. For some reason yet unexplained they decided to increase the corrosion resistance which is a quality nobody in the knife world was asking for. We wanted a tougher stainless, and S30V didn't really get us where we wanted to go, especially with the new problems it introduced.
 
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Jerry Hossom said:
Ha!! James, that is a sore subject with me, because I was clearly told at the time BY CRUCIBLE that S30V was to be a stainless CPM-3V, which clearly it never was. Ironically, I just learned why it wasn't from the current Chief Metallurgist at Crucible while at the Blade Show this year. It's too technically detailed to get into here, but the dirty little truth is that it was never intended to be a "stainless 3V"; it was intended to be a 3% CPM stainless, which got kicked up to 4% for some unknown reason. What it really is is a Vanadium laced 154CM made with the CPM process. Then, when they finally did get around to going after BG-42 with a CPM, they kept the Vanadium at 0.1% to control grain size instead of the 1.0% it is in BG-42, so CPM-154 happened and was in my judgement a disappointment. Not that CPM-154 isn't a great steel, it just could have been better. So they didn't ALWAYS listen. :)
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Hi Jerry,

And now we have CPM 4V... :D

I suppose you can think of it as a non stainless CPM S30V that is tougher and with a higher obtainable hardness.

Jim
 
The wealth of knowledge you have is truly amazing, thank you as well for chiming in...I love bladeforums its like a library of information at our fingertips for anyone who cares to find the answers they seek... having people like yourself around to just drop by and say some words is awesome thanks. I didnt think Dick barber misspoke when he said S30V was created as a knife steel.. considering he created it.
Jerry Hossom said:
Let me share something Dick Barber told me back when this whole thing was getting started. My guess is that it's still true today.

"We [meaning steel makers] really don't know how these steels are going to perform in a knife edge and that's why we're talking with you knifemakers. You need to tell us."

I think the fact that Crucible listened to what we said back then is why S35VN happened, and they should be commended for having listened and responded to the concerns that were expressed.
Click to expand...
 
Jerry Hossom said:
Edited to add: They didn't need to convert the Chromium to carbides if they just used less Chromium AND less Carbon. That is the enigma about what they were thinking. For some reason yet unexplained they decided to increase the corrosion resistance which is a quality nobody in the knife world was asking for. We wanted a tougher stainless, and S30V didn't really get us where we wanted to go, especially with the new problems it introduced.
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They would have ended up with something closer to ELMAX a lot earlier if they would have listened..... ;)
 
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