Questions about A2 steel

[bladeprince]

D2 is very popular. M2 is desirable at times and there are occasional offerings by some knifemakers. However, it seems the only company that uses A2 to any extent is Bark River Knives.

I have a couple of A2 Bark River's and I think the steel is great. Polishes nicely, resists stains, doesn't rust, and the most important, takes a razor edge and holds it as well as any of the other high end steels I have. I believe the Bark River heat treat takes it to 59-60 Rc. That's as hard as any other quality steel.

Why does Bark River seem to be the only [major] user of A2? Why do we not see other knifemakers using it? Is there something negative about A2 that I don't know about? Please educate me.

Regards

 

[3Guardsmen]

Why is does Bark River seem to be the only [major] user of A2? Why do we not see other knifemakers using it?

Regards

Are you aware of Chris Reeve Knives' "one-piece" line of fixed blades? Here you go: http://www.chrisreeve.com/onepiece.htm


Regards,
3G

 

[t1mpani]

John Greco used A2 for years, as did Busse before INFI. It's a very good blade steel--but it has the double whammy against it of being more difficult to work with than many other cutlery steels, and not having the new, steel-of-the-month appeal of S30V and some others. Marketability plays at least as big a part in most manufacturers' steel selection as does genuine performance.

I think BRKT's claimed HRC range is 59-60, though I seem to recall some posts from people who have done their own testing and found that the actual production numbers tend to run a point or two softer than that. I own some Bark Rivers myself and I definitely like their knives and how well they cut, but this really has more to do with the edge geometries they utilize than the type of steel. This isn't to say that their steel choice isn't a good one, but A2 really starts to show what it's made of at higher hardnesses (HRC 62+). I don't know of any manufacturers who are running it this hard--I think out of concerns for fragility. Ironically, it's actually more rugged at that hardness than it is a few points softer. Anyway, many custom makers work with it, and it has a pretty loyal following. It isn't stainless but is pretty easy to take care of, and while not what I'd call an abuse-oriented steel it's tougher than S30V, D2, and others of that ilk while still providing high edge strength and abrasion resistance. I personally prefer it in small to medium sized knives, though you'll see it in bigger stuff now and then.

 

[Dog of War]

I think BRKT's claimed HRC range is 59-60, though I seem to recall some posts from people who have done their own testing and found that the actual production numbers tend to run a point or two softer than that. I own some Bark Rivers myself and I definitely like their knives and how well they cut, but this really has more to do with the edge geometries they utilize than the type of steel. This isn't to say that their steel choice isn't a good one, but A2 really starts to show what it's made of at higher hardnesses (HRC 62+). I don't know of any manufacturers who are running it this hard--I think out of concerns for fragility. Ironically, it's actually more rugged at that hardness than it is a few points softer.

Very interesting. I've felt for some time that BRKT's blades are run softer than claimed and well below optimum .... with furniture makers in the family and my brother an industrial cutting tool designer I've had more than a little experience with A2 at higher hardnesses, and you're right that's where you really see the performance come out.

 

[t1mpani]

Good point; I should have said that no knife manufacturers are running it that hard--because you're right it certainly comes that hard and harder out in the tool industry.

 

[Dog of War]

In a thread on the Spyderco forum about possible changes to the Paramilitary I suggested a tool steel blade, specifically mentioning as example A2 at a decent hardness. Certainly there are tougher, higher wear tool steels, but IMO having modern folders available in something other than stainless would be real boon to enthusiasts .... and Spyderco seems like the one company out there that might try it.

Given that generations before us carried carbon steel-bladed knives including multi-blade slipjoints that sat deep in sweaty, dirty pockets, and apparently didn't have much of a problem maintaining them, it beats the hell out of me why we don't see more offerings in A2 and other tool steels. Hopefully threads like this will get noticed.

 

[phatch]

Mike runs A2 a bit soft so that it's easy to sharpen and maintain in the field.

Phil

 

[ohmyheckinslc]

Aren't Severtechs made with A2?

 

[OldPhysics]

Bladeprince,

I've had a CRK A-2 knife, one of his larger ones, for a little over a year now. I've taken it 'into the field' and treated it...well, like crap. Beat the heck out of it in every way possible. I even let my large and generally careless clan of children (teenagers and above) use and mis-use the blade.

I expected to at least see a chipped edge, maybe even a ragged one.

Nothing. Nada. Zilch. Zip. Blade remains in astoundingly good shape. Must admit, it isn't particularly easy to sharpen -- but must ALSO admit that I'm no sharpening expert!

A-2 may not have the 'sexiness' of S30V, but it is definitely high performance.

 

[t1mpani]

Mike runs A2 a bit soft so that it's easy to sharpen and maintain in the field.

Phil

Yes, I've heard that line of reasoning, and I'll admit it isn't a bad one. My own personal thought, however, is that by making it softer from the get-go, you pretty much guarantee that the edge will dull/impact/roll more quickly, thereby necessitating field maintenance that might otherwise be avoided, or at least not have to happen as frequently. Kind of a, "I made it easier to fix because it's more likely you'll need to" train of thought. I've always kind of questioned the whole field sharpening notion, anyway. If you are heading out to do enough work that you'll likely dull your knife, it makes a lot more sense to carry a small sharpening stone/rod/whatever with you than planning to rely on whatever rock you happen to be able to find; and if you're carrying something, it's no harder to carry a ceramic or diamond sharpener than it is an arkansas stone, so the steel hardness kind of becomes a moot point. Actually, my favorite field sharpening device is a couple pieces of folded up 3M sanding paper that I can just lay on top of my leg and strop--takes up absolutely no room in a pack or pants pocket and has never had any trouble biting into the harder steels.

 

[Rupestris]

Rapid River Knifeworks also uses A2 in all there offerings (asside fron their fillet knives - 154CM).

Mods, Please don't think this is spam. I don't work for 'em and I only have one of their knives. Just offering another A2 knifemaker. I know someone from there posted here without a membership and had to walk the plank.

 

[Cliff Stamp]

Mike runs A2 a bit soft so that it's easy to sharpen and maintain in the field.

Unless you are leaving it that soft that it can be readily filed then this has the opposite effect. You soften a steel by making the structure more coarse, it isn't a good idea for many reasons because the material properties are usually severely reduced. You are far better off moving to a steel which is designed to work at the lower hardness if that is what you want because it will be tougher, stronger and with a higher wear resistance than an underhardened steel. Carpenter explains this clearly in thier book on steel selection and shows the material data in detail to support it. Underhardening steels in general is a really bad idea. It is usually done simply because it is cheaper (no use of oil/cold) or you can temper higher and thus grind it hotter so avoid coolant, reduce time, etc. .

-Cliff

 

[bladeprince]

Unless you are leaving it that soft that it can be readily filed then this has the opposite effect. You soften a steel by making the structure more coarse, it isn't a good idea for many reasons because the material properties are usually severely reduced. You are far better off moving to a steel which is designed to work at the lower hardness if that is what you want because it will be tougher, stronger and with a higher wear resistance than an underhardened steel. Carpenter explains this clearly in thier book on steel selection and shows the material data in detail to support it. Underhardening steels in general is a really bad idea. It is usually done simply because it is cheaper (no use of oil/cold) or you can temper higher and thus grind it hotter so avoid coolant, reduce time, etc. .

-Cliff

Cliff, I've alway appreciated your knowledge and comments but you sure know how to "stir the pot"...LOL. The Bark River forum on "knifeforums" is even talking about you now. I sure didn't know my simple little question about A2 would cause such a comotion.

 

[Dog of War]

Cliff, I've alway appreciated your knowledge and comment but you sure know how to "stir the pot"...LOL. The Bark River forum on "knifeforums" is even talking about you now. I sure didn't know my simple little question about A2 would cause such a comotion.

Over on those other forums, it's pretty much heresy to question anything one of the beloved mfgs/makers does. Not saying that Mike Stewart is a bad guy or anything (he is controversial) or even that I don't think Bark River makes a pretty good knife, they do IMO, but whenever you find someone talking about secret heat treatments or something like that, it's not a good sign.

Mike has always made a big deal about BRKT's outsourced heat treatment but what puzzles me is that the performance just isn't there, at least given Mike's claims that it is sophisticated and costly. Camillus' 0170-6C (50100-B) is a commodity steel and as far as I know probably receives a pretty basic heat treatment - at least I've never seen Camillus brag about 6 different tempers and yada yada - yet in my tests it outperforms BRKT's A2 for edge retention. In fact the simple 1095 tool steel that Eriksson uses in their Mora knives costing less than $10 has better edge retention.

In that thread on knifeforums you'll notice that nothing specific is said to counter points made by several of us in this thread. Instead, just a few loose comments, and of course some mild personal attack:

We have tried them harder and when I can drop a 60-61 A-2 Blade on the floor and have it Break in half--I don't call that Shining. I call that too hard.

It's easy to be an expert.

All you need is a Keyboard to type stuff you don't know anything about.

The Solution is very simple--They need to start their Own Knife Company.

Our Heat Treat is not like others and we do a Triple Temper --Twice in the Cycle- on Every Blade. All 6 tempers are at Different Temperatures.

It is my own way of doing it and I don't share it.

I have used the same method of Heat Treat--Temper and Cryo since I introduced the Trailguide--in A-2-- at Blackjack in 1994. I even still Draw the Tangs Softer--I think I'm the only Company Still doing that.

I'll Quote My Old Friend and Knifemaker in japan--Harumi Suzuki-- " Easy to Say--Hard to Do"

Anyway, this is exactly why I prefer the discussions on BFC ..... there actually are discusssions here, and the words of experts aren't just accepted blindly.

 

[t1mpani]

The Bark River forum on Knifeforums has lots of good information, and good, knowledgeable participants who are very happy to answer questions. However, they are prone to, let's say, a certain Jekyll and Hyde quality when someone has the temerity to suggest that something BRK&T has produced might possibly be made even better if done slightly differently. A while back I was commenting on the Bark River "Teddy" knife which I had had the oppurtunity to handle and was very impressed by, and also made mention of the unusually good quality of the factory sheath. Almost as an aside, I mentioned that--had I my preference--I would have the keeper strap go over the top guard instead of the lower, since this keeps those keepers from coming into contact with the blade. I also mentioned, though, that unless one goes custom, one can hardly expect to get something EXACTLY the way you'd like it, and that overall I thought it was a very nice setup.

I swear--you would have thought I'd claimed Mike Stewart eats babies while kicking puppies. The impassioned condemnation of my "derogatory" comments about the sheath keeper system were truly a sight to behold.

My point being, don't worry too much about that particular forum over there when they get to venting--they're more than slightly touchy. At the same time, though, don't write them off, either...lots of good knowledge there, and they're happy to share it.

 

[cdf]

I'm am A2 fanboy , would like to see it more often .

Chris

 

[Danbo]

I love A2, and would like to see more of it being used. And, I'd like to see the factorys using it, up the Rockwell hardness to around 60.

 

[Esav Benyamin]

Mission Knives uses A2 as well as their beta titanium.

 

[Cliff Stamp]

The Bark River forum on "knifeforums" is even talking about you now.

That would be the differnence between us, I will talk about the steel, I'll also tell you the details to support the arguements I have made, I'll provide you with the materials references from multiple sources as well as the knives I have used.

... in my tests it outperforms BRKT's A2 for edge retention. In fact the simple 1095 tool steel that Eriksson uses in their Mora knives costing less than $10 has better edge retention.

That isn't surprising, I would expect a lot of retained austenite in underhardened A2. In fine edges that falls apart, you can see this in Beach's and Elliott's A2 planer blade tests. However as I have said many times, don't use results like these to judge the steel. Look at the materials data, see where it maximizes performance, try a blade there and if it still has low performance then contact the manufactuer of the steel, confirm it, and then write it off - assuming you somehow have a way to explain the contrast between the materials data and the expected performance.

We have tried them harder and when I can drop a 60-61 A-2 Blade on the floor and have it Break in half--I don't call that Shining. I call that too hard.

I call shenannigans. This is completely absurd, first off the extreme minima that some steels have comes from tempers which lie along carbide precipitation ranges. Ironically enough, this happens to a lot of steels when they are tempered to draw back the hardness, yes, they get more brittle as they also get softer and weaker (and lose wear/corrosion resistance - like I said, it is a bad thing to do). A2 will in fact do that, but not nearly so dramatic.

A2 simply doesn't have the carbide volume to induce such a change. You will see such large responces in M2 and similar steels where the toughness can drop to a small fraction of the minimum. However none of the materials data for A2, torsional or charpy/izod show such behavior, because as noted, the carbide precipitation problem isn't that much of an issue. Makers also run at A2 at that hardness and their blades do not have that performance.

Our Heat Treat is not like others and we do a Triple Temper --Twice in the Cycle- on Every Blade. All 6 tempers are at Different Temperatures.

Fowler actually does the entire heat treatment three times, read Cashen's comments on if that is actually productive and check the materials data he provides to find some arguement for that level of complexity. Any arguement for exactly what each part in this complex cycle is doing which is supported by actual published materials science? Nope.

However, they are prone to, let's say, a certain Jekyll and Hyde quality when someone has the temerity to suggest that something BRK&T has produced might possibly be made even better if done slightly differently.

That isn't restricted to BRK&T, it happens whenever any maker runs a forum they moderate and they don't actively prevent such behavior. All you are seeing is the cult mentality that forms in any club house. But if you really feel those are the types of places which are ideal for discriminating information, well, I have a few people in real estate who would be very interested in talking to you.

-Cliff

 

[t1mpani]

But if you really feel those are the types of places which are ideal for discriminating information, well, I have a few people in real estate who would be very interested in talking to you.

Not at all, Cliff--I was merely pointing out that they ARE capable of passing along good info, so long as you don't rub them the wrong way. Of course, the fact that's it's not all that difficult to rub them the wrong way was the other object of my post.