Toughest stainless?

D

dogrunner

Joined
Dec 26, 2003
Messages
1,524
Ankerson and others contributing to his thread have done an awesome service in quantifying edge-holding performance of steels of all sorts. There is also a lot of additional information in that thread and others, but what I am looking for specifically is some sort of comparable quantification/measurement of toughness / resistance to breakage. I know knives are for cutting and should only be used with extreme care and delicacy :) and I am not interested in extreme destruction tests. Steels are pretty tough, but the clear high performers are are the tool steels such as 3V and S7.

There is still commentary on toughness of steels considered in the stainless category (good rust resistance of steels like 3V not withstanding).
So, does anyone have any "real-world" data (comparable to Ankerson's for edge holding) for toughness of stainless steels such as S90V, M390, Elmax, S30V, S35VN, 154CM, CPM 154, VG10, etc?

By real-world I mean toughness of the knife (standardized by blade length, thickness, grind, etc - all those things that determine how much force a knife can absorb before breaking) and not of the specs on a steel composition sheet. Not broad brush strokes either (like PM steels tougher than non-PM counterparts, although that may be true too).

Why do I want to know this? Because all tools are a compromise and getting one with awesome edge-holding might not be the one you would bring on an expedition to a remote location (well, I'm bringing 3V, but wanted to know what the options were in stainless too :).

thanks
 
I expect the best you can get is people's personal experiences. It would take testing similar sized slabs of different steels being subjected to machine testing to find out which is king.

Speaking of personal experience though I can tell you S35VN impressed the hell out of me on my last trip in the Belgian Ardennes. I trust that steel enough that I would carry it into a survival situation.
 
There are compilation-charts of Charpy or Izod impact-toughness for various steels including the stainless steels mentioned, "real-world" tests, but they are performed on bar-stock standards, not knife edges with much thinner geometry, and attention must be paid to when manufacturers describe transverse vs longitudinal impact toughness. Impact toughness is measured in Joules of energy absorbed by the material prior to fracture. Usually only the longitudinal values are relevant even to knife users, and those are higher. In Charpy C-notch tests, most stainless steels, be they PM or Ingot, fall within 15 - 35 J impact toughness while simple tool steels like O1 fall ~40 J. Generally speaking, larger carbides result in lower toughness and larger sections of edge-loss upon fracture, smaller carbides result in higher toughness and smaller sections of edge-loss. With high-carbide steels, the point is to maximize wear-resistance while not losing toughness. PM-technology allows for previously unattainable carbide volume (i.e. much higher wear-resistance) without sacrificing toughness. That said, few stainless steels have been able to breach 40 J impact toughness (both M390 and Elmax may, but iirc the impact tests used for those were unnotched so may read higher than is normally the case).
 
dogrunner said:
Ankerson and others contributing to his thread have done an awesome service in quantifying edge-holding performance of steels of all sorts. There is also a lot of additional information in that thread and others, but what I am looking for specifically is some sort of comparable quantification/measurement of toughness / resistance to breakage. I know knives are for cutting and should only be used with extreme care and delicacy :) and I am not interested in extreme destruction tests. Steels are pretty tough, but the clear high performers are are the tool steels such as 3V and S7.

There is still commentary on toughness of steels considered in the stainless category (good rust resistance of steels like 3V not withstanding).
So, does anyone have any "real-world" data (comparable to Ankerson's for edge holding) for toughness of stainless steels such as S90V, M390, Elmax, S30V, S35VN, 154CM, CPM 154, VG10, etc?

By real-world I mean toughness of the knife (standardized by blade length, thickness, grind, etc - all those things that determine how much force a knife can absorb before breaking) and not of the specs on a steel composition sheet. Not broad brush strokes either (like PM steels tougher than non-PM counterparts, although that may be true too).

Why do I want to know this? Because all tools are a compromise and getting one with awesome edge-holding might not be the one you would bring on an expedition to a remote location (well, I'm bringing 3V, but wanted to know what the options were in stainless too :).

thanks
Click to expand...

The Fällkniven company has done break tests at the Technological Institution of the Luleå University, located in the northern part of Sweden.
On the FK homepage, they show the results on a few of their models.
For example, the current laminted VG-10/420j2 F1 model breaks at 108 Joule, with a lever lenght of 109 millimeter.


Regards
Mikael
 
hey Dog

I've looked into this same thing on a number of occasions and from all of the searching i've done on this over the last couple years it seems Elmax is pretty close to as tough as you get for a stainless steel. If I'm not mistaken it can be almost twice as tough as CPMS35VN at rocwell 58/59 and will be able to be pushed into the low 60s and still be as tough. That's not a knock against CPMS35VN... it's a very tough stainless and i have done some "toughness testing" with it myself and can confirm it's more than adequate, but rather a testament to just how tough Elmax can be.

P.S. all my research on Elmax toughness is from the internet so take it for what it's worth.
 
I use a ZT in Elmax a lot, the steel has really impressed me a lot, outperforms everything else I've owned by a long shot. Sadly that's not saying much since VG-10 and AUS-8 were my best steels prior, but I've been very impressed by the Elmax. The only knife that comes close for toughness is the carbon-bladed Mora I use as my camp knife. (UHB-20C steel from what I've found the interweb)
 
Mikael W said:
The Fällkniven company has done break tests at the Technological Institution of the Luleå University, located in the northern part of Sweden.
On the FK homepage, they show the results on a few of their models.
For example, the current laminted VG-10/420j2 F1 model breaks at 108 Joule, with a lever lenght of 109 millimeter.


Regards
Mikael
Click to expand...

Man you always so hilariously pro-fallkniven
 
A.L. said:
Man you always so hilariously pro-fallkniven
Click to expand...

A.L.!

:D Nice to be to Your amusement!
I do use their knives a lot, but also other brands like Bark River, Mora, Solingen made and a few others.

Nevertheless, Fällkniven are one if not the only company, who has showed numbers and graphs on real breaktests.
This is facts and I think this is what the OP asked for.

On a personal note, I'm always open for trying other brands, if they are of high quality!
Do You have any suggestions?
If so, feel free to send me a PM, not to hi-jack the thread.


Regards
Mikael
 
Last edited:
Mikael W - thanks for the link. I am a Fallkniven fan too and have an older (non-lam) F1 that seems like a pretty sturdy knife.

I was never that interested in Elmax, until I saw Nathan the Machinist's video (fwiw) and descriptions on his for sale threads some time ago. He was offering his knives in either 3V or Elmax and (again fwiw) struck me as the type who would go where his experience with performance led (i.e. not necessarily hung up on marketing but more on actual performance).

I also see companies with a reputation for building heavy-duty blades or at least marketing to that crowd using Elmax a lot (ZT) or S35VN (Spartan, Chris Reeves). Mike Stewart/Bark River has repeatedly stated on another forum that S35VN is his pick for a tough stainless. Everyone has his / her opinion, but as far as actually putting knives to the test (for toughness, where you might break a knife as opposed to edge holding, where you just dull it), there does not seem to be much beyond opinion.

So I thank everyone who has posted their thoughts or experiences or sources of information. At least we get a sense of what is known or not. And my guess is there are a lot of great steels these days that will take a lot of abuse (intentional or otherwise).
 
Not wishing to get yelled at but seriously, does anyone think that the locals of say some remote Indonesian village using some unknown (to them, steel) parang made from a truck leaf spring with additional carbon added (I've been at these forges) is worried about whether their steel alloy is XX something or other, or that the parang might break, not hold an edge etc etc in their everyday life and everyday usage of this tool (used for everything just about)? If you have used these tools and I have, you will know they definitely hold an edge and can also take an edge, from chopping down coconuts up 60 ft in the air to clearing the undergrowth of farmland.
What I'm trying to say here is we often get way too carried away with the alloy composition and forget about what we are actually going to use the knife/tool for and in what particular environment.
Who, for example here, has actually broken a knife by not abusing it? ( I don't mean a manufacturers fault either, eg brittle fracture failure etc). As one company says their knives are "almost indestructible" but will break if subjected to enough stress. Unfortunately I have been involved in survival situations, (even one where the threat was from other humans) despite having a knife for all of these unpleasant occasions it did not play a role in my or my fellow companions "survival" But if you are going to lever open steel doors, smash a knife blade with a rock or steel hammer, attempt to cut rocks or steel cable/wire then I guess no knife will hold it's edge not eventually break etc.
Toughness, unless scientifically standardized ( as is ) is relative and as basically said above, tests would need to be carried out on the same model, same grind and geometry but in different alloys and cutting/hitting/bending on standardized objects/tests to make any sense and even then you are not likely to be conducting similar activities on your "expedition" unless it's into a laboratory LOL. You can't actually do "real world tests" in a sense when you think about it only based on as NetShadeX said, personal experience and of course the influence of marketing hype from steel and knife manufacturers as to which steel alloy is the holy grail.
 
  • Like
Reactions: vba
I've just been field testing a knife made from ELMAX and actually cryogenically treated as apposed to just sub zero temps. It is ( it didn't break LOL) a TRC K1, and I'll put a link at the bottom here. Anyway the tests were simply usage of this knife under conditions you might encounter camping and hunting and fishing. How did the edge hold up after 3 weeks constant usage? Well pretty good and I did have to touch it up once with some ceramics. It just so happen that the edge bevel matched exactly the angle of the ceramic sharpener so I used this to essentially really only take out the grinding marks on the bevels (if that counts as "touching up" probably not in some people books). The edge never chipped during use but then I didn't bash it into rocks or subject it to say puncturing fuel tanks/tyres/cutting hydraulic hoses etc. Why I didn't do this was because as discussed with the manufacturer, this knife was clearly not designed for military usage. Certainly my conversations with Uddeholm and their literature state how "tough" this alloy is but they are really referring to it's usage in the tool steel industry cutting abrasive plastics etc.
 
A very interesting topic.

We all agree that for toughness stainless steel may not be the best choice.

But rating the toughness of stainless steel for knife blades does have merit.


...it seems Elmax is pretty close to as tough as you get for a stainless steel...
Click to expand...


Bark River's Mike Stewart, who has been recently testing Elmax for use in his products, rates CPM-154 and CPM-S35VN tougher then Elmax.

Of course that's at the Hardness and with the HT he's using on his blades.

More shocking is 12C27, :eek: let me quote:


Sandvik 12C27 is Tougher than ALL of the CPM or Powdered Stainless steels at the same Rockwell...

...At 58rc you can bend 12C27 almost to 90 degrees without breaking it.

BUT........

It does not have anywhere the edge holding of any of the CPM or Powdered Stainless Steels.
Click to expand...


Just some food for thought.



Big Mike
 
I could believe that 12c27 is one of, if not the toughest cutlery steel in use today. Although I personally have not abused my Opinel Inox, I have seen people chop wood with an Opinel 13, which has a very thin 12c27 blade, without any sign of damage.
 
Thank you Mike

I've recently switched to 12c27 myself for this very reason... just didn't mention it because i had always understood that Elmax was the king of toughness for stainless and nobody seems to think the sandvic steels are sexy enough to merit conversation. I'll caveat that by saying that prior to 12c27, i had used 440c for 10+ years with absolutely no problems... and on 3 tours overseas and multiple training missions, I have thouroughly used and abused some of my 440C blades way beyond what most people would consider "acceptable use" for a knife and i never damaged one to the point where it wasn't still there for me when i came home. All kidding aside, most steels will do more than enough for most people if the heat treat and geometry is designed for a given task.
 
dogrunner said:
Mikael W - thanks for the link. I am a Fallkniven fan too and have an older (non-lam) F1 that seems like a pretty sturdy knife.

I was never that interested in Elmax, until I saw Nathan the Machinist's video (fwiw) and descriptions on his for sale threads some time ago. He was offering his knives in either 3V or Elmax and (again fwiw) struck me as the type who would go where his experience with performance led (i.e. not necessarily hung up on marketing but more on actual performance).

I also see companies with a reputation for building heavy-duty blades or at least marketing to that crowd using Elmax a lot (ZT) or S35VN (Spartan, Chris Reeves). Mike Stewart/Bark River has repeatedly stated on another forum that S35VN is his pick for a tough stainless. Everyone has his / her opinion, but as far as actually putting knives to the test (for toughness, where you might break a knife as opposed to edge holding, where you just dull it), there does not seem to be much beyond opinion.

So I thank everyone who has posted their thoughts or experiences or sources of information. At least we get a sense of what is known or not. And my guess is there are a lot of great steels these days that will take a lot of abuse (intentional or otherwise).
Click to expand...

Dogrunner, I think it's interesting and fun to try out the new steels!
I have a few in powdersteels (not Elmax or S35VN) and I do like them, but a carbonsteel knife is still very good in my book.
It's more about Geometry and Heat-Treatment, before the Steel.
The new PM stainless steels are indeed nice and I use them side by side with my carbonsteel knives.

If You have the opportunity to get a couple of knives from Nathan, I think You should give it a go!
It sounds like a fun way of learning about the newer steels.



Regards
Mikael
 
FCCBCT said:
Not wishing to get yelled at but seriously, does anyone think that the locals of say some remote Indonesian village using some unknown (to them, steel) parang made from a truck leaf spring with additional carbon added (I've been at these forges) is worried about whether their steel alloy is XX something or other, or that the parang might break, not hold an edge etc etc in their everyday life and everyday usage of this tool (used for everything just about)? If you have used these tools and I have, you will know they definitely hold an edge and can also take an edge, from chopping down coconuts up 60 ft in the air to clearing the undergrowth of farmland.
What I'm trying to say here is we often get way too carried away with the alloy composition and forget about what we are actually going to use the knife/tool for and in what particular environment.
Who, for example here, has actually broken a knife by not abusing it? ( I don't mean a manufacturers fault either, eg brittle fracture failure etc). As one company says their knives are "almost indestructible" but will break if subjected to enough stress. Unfortunately I have been involved in survival situations, (even one where the threat was from other humans) despite having a knife for all of these unpleasant occasions it did not play a role in my or my fellow companions "survival" But if you are going to lever open steel doors, smash a knife blade with a rock or steel hammer, attempt to cut rocks or steel cable/wire then I guess no knife will hold it's edge not eventually break etc.
Toughness, unless scientifically standardized ( as is ) is relative and as basically said above, tests would need to be carried out on the same model, same grind and geometry but in different alloys and cutting/hitting/bending on standardized objects/tests to make any sense and even then you are not likely to be conducting similar activities on your "expedition" unless it's into a laboratory LOL. You can't actually do "real world tests" in a sense when you think about it only based on as NetShadeX said, personal experience and of course the influence of marketing hype from steel and knife manufacturers as to which steel alloy is the holy grail.
Click to expand...

FCCBCT,
Interesting thoughts and I agree, I have seen Indonesians using their big carbonblades and they sure know what they are doing!


Regards
Mikael
 
  • Like
Reactions: vba
Big Mike said:
A very interesting topic.

We all agree that for toughness stainless steel may not be the best choice.

But rating the toughness of stainless steel for knife blades does have merit.





Bark River's Mike Stewart, who has been recently testing Elmax for use in his products, rates CPM-154 and CPM-S35VN tougher then Elmax.

Of course that's at the Hardness and with the HT he's using on his blades.

More shocking is 12C27, :eek: let me quote:





Just some food for thought.



Big Mike
Click to expand...


Mike Stewart sure knows how to get the best out of the steels he uses and I'm very impressed with Bark River 12c27 knives!


Regards
Mikael
 
Rostislav said:
I could believe that 12c27 is one of, if not the toughest cutlery steel in use today. Although I personally have not abused my Opinel Inox, I have seen people chop wood with an Opinel 13, which has a very thin 12c27 blade, without any sign of damage.
Click to expand...

Chop with 12c27?

rd1t.jpg


Absolutely!


Regards
Mikael
 
rustyrazor said:
Thank you Mike

I've recently switched to 12c27 myself for this very reason... just didn't mention it because i had always understood that Elmax was the king of toughness for stainless and nobody seems to think the sandvic steels are sexy enough to merit conversation. I'll caveat that by saying that prior to 12c27, i had used 440c for 10+ years with absolutely no problems... and on 3 tours overseas and multiple training missions, I have thouroughly used and abused some of my 440C blades way beyond what most people would consider "acceptable use" for a knife and i never damaged one to the point where it wasn't still there for me when i came home. All kidding aside, most steels will do more than enough for most people if the heat treat and geometry is designed for a given task.
Click to expand...


I agree!


Regards
Mikael
 
You must log in or register to reply here.
Back
Top