ATS34=fragile 440V=soft M2=hype: Steel Gossip

JeremyW · Apr 25, 2001

Forgive a newbie for bringing up an issue that might seem obvious and clear to some. Im just trying to make sense of all the steel talk Ive heard and overheard. Here we go:

ATS-34 is by now a time-honored blade steel that for some reason has lately been accused of being too brittle and susceptible to chipping.

ATS-55: can it really be ATS34-like without the molybdenum?

440V looks like an excellent steel on paper. By its composition it is a rich steel packed with elements that you think would be perfect for a knife steel (high carbon, chromium, vanadium, some molybdenum). Judging by what steel producers say about it, 440V is very resistant to wear. However, this steels tendency to brittleness has made knife manufacturers refrain from putting a hard heat treatment on it (even at blade lengths under 3.5 inches). HRC values of 55-56 make even me suspicious of a knife. Some say that this makes the blade too soft to hold its edge. Others say that while these blades cannot take keen edges, because of the vanadium they will take a dull edge and hold it forever. Ive also heard some say that its lack of toughness means this steel can never be a good edge holder, even at high hardness.

BG-42: Is it _really_ be an improvement on ATS-34? Is it not made a bit too brittle with the 64 HRC jobs some manufacturers are putting on this steel? How does it compare with 440V, which is similar except that it exchanges the molybdenum for even more vanadium (while adding nearly twice the carbon).

M2 has a lot of people speaking its praise. However, aside from the presence of tungsten (which helps at high temps) on paper this steel isnt impressive at all, especially when compared with component-rich steels like 440V. Some say that, apart from high speed/temperature applications, it is no better than A2. It also seems to have gotten some (undue?) support from the all stainless steels are inferior crowd. Is it really worth the extra $50+, especially in cases where toughness and extreme heat are not the most pressing issues (like small folders)?

52100-B (0170-6C): What of 52100-B? Ive heard nothing (good or bad) about this steel (but Id like to).

In the case of each of these steels (except 52100), Ive encountered at least one person who proclaims it as the premier steel, and (in the case of most of them) at least one person who claims it is so worthless that they would never buy a knife of this steel from any maker.

What conclusion is a newbie to draw? I ask because I am considering the Spyderco Native (440V), Benchmade mini-AFCK (M2), Benchmade Ascent (ATS-34), Spyderco Endura (ATS-55), SOG X42 (BG-42), and the Becker Companion (0170-6C).

-Jeremy

Paracelsus · Apr 25, 2001

Properly heat-treated, all of those steels will make outstanding blades. There simply is no Best steel for all things.

Makers touting very high RC values will tend to produce more brittle steel. Most steels at RC 56-58 made very good knife blades. Some steels will still perform well at even higher RC values. Very few steels can actually be hardened to RC64, and if they can be made that hard, will probably be too brittle for a general purpose knife. Other steels may be too brittle at RC58. It all depends on the heat-treatment. Two blades made from the same steel and tempered to the same RC value may perform quite differently. Blade metallurgy is a very complicated process. The resistance to penentration (RC value) alone is insufficient information to allow comparison of steels.

Depending on the heat-treatment, final hardness, blade geometry, etc, some of these steels may be better choices than others. The elemental composition of the steel is a clue to its potential, but does not tell you everything.

You should have no real worries about any of the steels you mention. There is entirely too much focus around here on the 'best' steel. There is just no such thing. All steels are compromises in one way or another.

Paracelsus

Chang · Apr 25, 2001

Jeremy: I too have heard that ATS-34 is brittle, but I have never chipped any blade made from ATS-34 (or 154-CM, it's American made equivalent). Then again, all the ATS-34 blades I've had were folding knives that don't see any extra hard usage.

[This message has been edited by Comrade Chang (edited 04-25-2001).]

Gator97 · Apr 25, 2001

I don't have all the steels lienlisted in your messages, and with some of them I haven't done any testing, e.g. my 440V Kershaw Onion BOA is still unused

However I could comment on 2.

Originally posted by JeremyW:

M2 has a lot of people speaking its praise.
Me too

However, aside from the presence of tungsten (which helps at high temps) on paper this steel isnt impressive at all,

Wel, as you said yourself above, the paper doesn't realy show the true pic always

Or
whatever the papaer says is being interpreted in different ways.

Is it really worth the extra $50+, especially in cases where toughness and extreme heat are not the most pressing issues (like small folders)?
It was exactly 2 relatively small folders, 940 Osborne in 154 CM(your favorite ATS-34 is a copy of it) and M2 710 that I've cut the same wires the other day. While M2 had thinner edge it handled the task fine, but 154 CM chipped in several places.

------------------
zvis.com
Have Fun,
Alligator

Ron Andersen · Apr 25, 2001

Para said it best:

Properly heat-treated, all of those steels will make outstanding blades. There simply is no Best steel for all things.

Being a knife manufacturer using BG-42 (and one named in Jeremy's post), I thought I'd jump in here for a moment. Latrobe has given us guidelines that BG-42 can be hardened up to Rc 64 for our knives, and we advertised our range for BG-42 blades as Rc 62-64. But we are convinced that for our purposes, Rc 62 is where we are to be hardening these blades, and "Rc 62" is stamped on the X-42 Recondo.

I'm only inserting this to clear up that SOG is not "shooting for Rc 64" with our BG-42 knives. We've had some questions along this line.

------------------
Ron Andersen
Consumer Services Manager
SOG Specialty Knives, Inc.

Website: www.sogknives.com
Email: ron@sogknives.com

[This message has been edited by Ron@SOG (edited 04-25-2001).]

Jeff Clark · Apr 25, 2001

Read Joe Talmadges steel FAQ (again?). It does discuss both relative merits of the alloys and the advantages of the alloying elements.

http://www.bladeforums.com/features/faqsteel.shtml

As I always say, adding vanadium to alloys makes them take a sharper edge. The vanadium carbides are hard but the vanadium helps to make the grain structure of the steel fine. Cutlery alloys have been adding vanadium for years. Strangely enough, tungsten also tends to make for sharper edges.

The thing that I generally don't want much of is molybdenum. It seems to make alloys that are particularly hard to sharpen. It shows most of its advantages at high temperatures.

I like my BG-42 blades better than my 440V blade. Up a little above 60RC it does a real nice job. I've used my BG-42 hunting knife to chop bone with no damage. It takes a nice shaving edge and holds it.

[This message has been edited by Jeff Clark (edited 04-25-2001).]

Joe Talmadge · Apr 25, 2001

Originally posted by JeremyW:

ATS-34 is by now a time-honored blade steel that for some reason has lately been accused of being too brittle and susceptible to chipping.

Well, depending on heat treat, you might see a lot of different behavior in ATS-34. Some ATS-34 is tougher than other ATS-34. I've definitely run into ATS-34 I'd consider outright brittle -- my old Benchmade ATS-34 blade chipped when it had 20-degree bevels, for example. On the other hand, my newer Benchmade ATS-34 blade doesn't chip even with 15-degree bevels. And, certainly, you won't find ATS-34 that's as tough as M-2, and certainly not one that can touch, say, 5160.

440V looks like an excellent steel on paper. By its composition it is a rich steel packed with elements that you think would be perfect for a knife steel (high carbon, chromium, vanadium, some molybdenum).

Does it really look good to you on paper? To me, it looks terrible. Packing a steel with so much alloying elements is definitely not necessarily a recipe for a great steel. Steels can lose a lot of toughness when packed with alloys, especially very high carbon and chromium. The only reason this steel works at all is because Crucible invented an entirely new manufacturing process to go along with it. If it were manufactured as an ingot steel, like every other steel on your list, it would be a disaster.

Which brings me around to the main point -- you may be paying too much attention to what the steel has as alloying elements.

The position that Cliff Stamp takes on this steel (and hopefully I'm not mangling it too much) is that at high hardness, it's very wear resistant but brittle. At lower hardness, it's still impressively wear resistant (though now it doesn't have the huge advantage over, say, ATS-34 anymore), but because it's so soft it lacks strength.

BG-42: Is it _really_ be an improvement on ATS-34? Is it not made a bit too brittle with the 64 HRC jobs some manufacturers are putting on this steel? How does it compare with 440V, which is similar except that it exchanges the molybdenum for even more vanadium (while adding nearly twice the carbon).

I think you're looking at the wrong steel! BG-42 has 1.2% Vanadium, 440V is 5%. A more accurate way to think of BG-42 is similar to ATS-34, except for two crucial differences:

1. BG-42 contains vanadium
2. BG-42 is manufactured through the VIM/VAR (vacuum remelting) process. ATS-34 is manufactured through the Argon/Oxygen/Decarburization (AOD) process.

These changes make BG-42 cleaner and finer-grained, for better toughness, better edge-taking. Can it take 64Rc? I dunno. But it's tougher than ATS-34, so you should be able to harden it more than ATS-34 and still get comparable toughness.

M2 has a lot of people speaking its praise. However, aside from the presence of tungsten (which helps at high temps) on paper this steel isnt impressive at all, especially when compared with component-rich steels like 440V. Some say that, apart from high speed/temperature applications, it is no better than A2.

I consider the phrase "no better than A2" to be quite a compliment. I've seen it behave differently than A2 though, being less tough but having better edge holding.

Compared to ATS-34 and 440V, M2 is much tougher at similar hardness, and that's its main draw. It means that on an M2 blade, you can take the edge thinner for better cutting performance, and still end up with a more robust edge.

52100-B (0170-6C): What of 52100-B? Ive heard nothing (good or bad) about this steel (but Id like to).

50100-B was, and still probably is, what Cold Steel's Carbon V is made from. Anything you hear that's good about Carbon V -- and you'll hear plenty, it's a good steel -- applies to 50100-B. 50100-B is 50100 steel, modified with vanadium.

Or you might be talking about 52100, another excellent alloy steel.

In the case of each of these steels (except 52100), Ive encountered at least one person who proclaims it as the premier steel, and (in the case of most of them) at least one person who claims it is so worthless that they would never buy a knife of this steel from any maker.

Good! Glad to see we're keeping you confused

What conclusion is a newbie to draw? I ask because I am considering the Spyderco Native (440V), Benchmade mini-AFCK (M2), Benchmade Ascent (ATS-34), Spyderco Endura (ATS-55), SOG X42 (BG-42), and the Becker Companion (0170-6C).

-Jeremy
[/B][/QUOTE]

rdangerer · Apr 26, 2001

Grossly simplified, and ignoring corrosion resistance desires, knife steel selection can (should? must?) be made based on intended use, and intended use drops into three general categories:

1. knives to be used primarily for slicing stuff and won't see chopping or harsh push cutting into potentially hard debris.
2. knives that will see slicing and push cutting into potentially hard debris.
3. knives that will be used for chopping stuff or maybe prying (?), and of course can be used for slicing also.

Originally posted by JeremyW:
ATS-34 is by now a time-honored blade steel that for some reason has lately been accused of being too brittle and susceptible to chipping.

ATS-34 is primarily a good steel for corrosion resistant slicers. If it is chipping, it probably wasn't heat treated very well (or you are using it very hard).

ATS-55: can it really be ATS34-like without the molybdenum?

No, it can't. It's missing molybdenum carbides (as hard as tungsten carbide) at Rc72-77. ATS-55 is a lower cost, lower performance version of ATS-34. No free lunch.

Carbide particles vary in their hardness, depending on the type of carbide:

60-65 hardened steel
66-68 Rc for chromium carbides
72-77 Rc for molybdenum and tungsten carbides
82-84 Rc for vanadium carbides.

440V looks like an excellent steel on paper. By its composition it is a rich steel packed with elements that you think would be perfect for a knife steel (high carbon, chromium, vanadium, some molybdenum). Judging by what steel producers say about it, 440V is very resistant to wear. However, this steels tendency to brittleness has made knife manufacturers refrain from putting a hard heat treatment on it (even at blade lengths under 3.5 inches). HRC values of 55-56 make even me suspicious of a knife. Some say that this makes the blade too soft to hold its edge. Others say that while these blades cannot take keen edges, because of the vanadium they will take a dull edge and hold it forever. Ive also heard some say that its lack of toughness means this steel can never be a good edge holder, even at high hardness.

440V is a slicer. Not good for push cutting if you'll hit hard debris. Depends on heat treat, but my 440V Spyderco's take a great, toothy, grabby, and very sharp edge. But 440V has brittleness problems indeed, witness Spyderco's revision downward of their hardness spec based on customer experience. 440V is also not as corrosion resistant as 420V, despite having more chrome. Weird, that, but straight from Crucible. Prediction: 440V will eventually be replaced by 420V or some other steel in the production market (already has been to a large degree in custom market).

BG-42: Is it _really_ be an improvement on ATS-34? Is it not made a bit too brittle with the 64 HRC jobs some manufacturers are putting on this steel? How does it compare with 440V, which is similar except that it exchanges the molybdenum for even more vanadium (while adding nearly twice the carbon).

Yes, if the maker spends time perfecting BG-42's heat treatment, it can be better than ATS-34 in nearly every way, but not in a dramatic fashion... Edge holding, toughness (slight benefit), corrosion resistance. BG-42 may be one of the best balanced of the high end steels going right now. BG-42 is essentialy ATS-34 with a 1.2% dose of Vanadium which should both add hard carbides for better wear resistance, and help to refine the grain structure when heat treat is optimized.

We'll see if Crucible can deliver on their "Stainless 3V" product S30V... which if really as they hope and are attempting to deliver, could be the best balanced steel on the market.

And Rc64 is too hard for any steel we commonly see used for knife blades (machine tools are frequently this hard, but they are brittle and must be used properly). In this range, if you drop the knife on a hard surface, it just might break into two big pieces. Seriously. Caveat Emptor. Wilson (D2 @ Rc62-64) & SOG (BG-42 @ Rc62-64) will learn their lessons if they truly allow their heat treat to stray that high. Rc61-62? Ok for some steels. Rc 62-64? Too high for about anything.

M2 has a lot of people speaking its praise. However, aside from the presence of tungsten (which helps at high temps) on paper this steel isnt impressive at all, especially when compared with component-rich steels like 440V. Some say that, apart from high speed/temperature applications, it is no better than A2. It also seems to have gotten some (undue?) support from the all stainless steels are inferior crowd. Is it really worth the extra $50+, especially in cases where toughness and extreme heat are not the most pressing issues (like small folders)?

M2 contains a bunch of goodies... 4.75-6.25% Moly, 5-6.75% Tungsten, 2.25-2.75% Vanadium. Those ARE the 3 major hard carbide formers. M2 has a low amount of chromium (3.75%-4.25%) which allows it to retain toughness at higher Rc's than most other cutlery steels. And of course, that chrome oxide layer isn't there to offer any real corrosion resistance either. A tradeoff. M2 is a great slicer, very good for push cutting into hard stuff, but I don't recall seeing it made into big choppers, but it could perform very well here if left in the Rc57-58 range. Have a book by Karl Shroen, he forges M2. He says "...outstanding qualities ... wear resistance, toughness, edge holding ... best I have seen in any steel currently in use for making knife blades". Karl also discussed D2 and Vascowear, BG-42, 10V and 440V. But he's forging and has obviously probably perfected his M2 heat treat. (see a pattern yet?)

Having said that, in a folding knife, particularly from Benchmade as they are the only onces using M2 right now, I suspect the performance gains over ATS-34 are subtle but noticeable under push cutting only (chopping with folder? duh...).

High speed or high temperature steels ... this matters for machine tools, where machining hard materials can get tools red-hot, and you want them to "not go soft" at truly red temperatures. "Red Hardness" is the term, and generally requires tungsten, and using tungsten seems to require a dose of moly & vanadium for some reason. Indeed, this red-hardness characteristic is of zero consequence for knives used by human hands. That misses the point though for knives used by human hands, as high speed tool steels have loads of hard carbides from the "3 biggies", and that translates into wear resistance (slicing performance). If chrome is low, you can get toughness if heat treated well (as a generalization). So, yeah, you don't need "high speed" or "red-hardness", but you might be able to use high carbide content.

52100-B (0170-6C): What of 52100-B? Ive heard nothing (good or bad) about this steel (but Id like to).

To clarify, 52100 and 0170-6 are not the same. 50100-B and 0170-6 are the ones that are the same steel.

Both very simple carbon steels. Can be made into tough blades that hold an edge well under heavy use. Rust easily. Can be differentially heat treated (soft/tough spine, hard edge for edge holding).

Some people have really optimized the 52100 heat treat (Montana crew, others). Makes a tough blade that holds an edge well, and a refined heat treat means fine grain structure, and that means fairly easy to sharpen and takes a wicked sharp edge.

In the case of each of these steels (except 52100), Ive encountered at least one person who proclaims it as the premier steel, and (in the case of most of them) at least one person who claims it is so worthless that they would never buy a knife of this steel from any maker. What conclusion is a newbie to draw?

It'll always be this way. You get to sort through the cr@pola like the rest of us, and hone your your BS filters and learn to read between the hype. You seem to be on the right track.

Heat treat matters. I wish it were simpler. That is the disappointing thing to learn ... you can't assume that a "super steel" is going to automatically make a super blade...the heat treat is totally critical. Bummer. It ain't that simple. Not so surprising, as few things in life are.

Edge holding for slicing is primarily a function of the steel matrix hardness, and secondarily but significantly a function of how rich the hard carbide content of the matrix is. A soft, high vanadium blade can make a poor edge-holder. A super simple (e.g. 1095) but hard edge (Rc-60) can hold an edge well. Key is to find tough steels that aren't brittle at high hardness.

Yeah, Stellite/Talonite is a weird exception that proves the rule (Co/Cr matrix looks "soft" to Rockwell indention tester, but is a tough matrix that holds a high concentration of hard tungsten & chromium carbides.)

What is too brittle? Depends on intended use. I am going to have Phil Wilson make me a semi-skinner of 420V at Rc62. I will only slice with it (clean animals). I won't drop it on hard surfaces. I'll have another knife along for tougher chores.

I ask because I am considering the Spyderco Native (440V), Benchmade mini-AFCK (M2), Benchmade Ascent (ATS-34), Spyderco Endura (ATS-55), SOG X42 (BG-42), and the Becker Companion (0170-6C).
-Jeremy

What do you want from these knives? What purpose?

Some short-phrased opinions:

Spyderco Native (440V): slicer
Benchmade mini-AFCK (M2): tough slicer/push cutter. Tough little folder.
Benchmade Ascent (ATS-34): general purpose slicer (I don't like Zytel)
Spyderco Endura (ATS-55): general purpose slicer, moderate performance
SOG X42 (BG-42): Should hold an edge for slicing very well, but don't drop it
Becker Companion (0170-6C): tough chopper blade material, but too short to chop. So why? I'd get the Brute or the Magnum Camp if I was going to tolerate an 0170-6 production blade.

YMMV.

[This message has been edited by rdangerer (edited 04-26-2001).]

Nail_dude · Apr 26, 2001

Cliff Stamp · Apr 26, 2001

rdranger :

I am going to have Phil Wilson make me a semi-skinner of 420V at Rc62.

That is interesting, the last time I talked to Phil about this I got the impression that it was difficult to get 420V over 59 RC if you temper it at all.

Concerning slicing, it is far more dependent on carbide structure than push cutting. Even with a very deformed edge a steel with a very agressive carbide structure can continue to cut very well as the carbides will rip through the material generating a cut path big enough for the deformed edge. You don't get the same benefit for push cutting, in fact optomizing for slicing (materials wise) can lead you directly away from high push cutting ability.

Concering "all steels make good knives", well you can make a knife with a very high cutting ability out of any steel, including simple mild steel. However durability and edge retention are a different matter.

There are huge differences in impact toughness, ductility, wear resistance and carbides structure among the various steels which allow you to make better knives out of the right alloy.

Basically you can make a knife more durable (give it a larger scope of work) or cut better (thinner at the same durability level), and at the same time have the edge last longer and be easier to sharpen.

I would agree however that simply picking a high quality steel does not make a high quality knife. You also need to get a maker who can do a heat treat to optomize its abilites and grind accordingly. Unfortunately deciding on those two factors is even harder than picking the steel.

-Cliff

Joe Talmadge · Apr 26, 2001

Original question:

ATS-55: can it really be ATS34-like without the molybdenum?

rdangerer:

No, it can't. It's missing molybdenum carbides (as hard as tungsten carbide) at Rc72-77. ATS-55 is a lower cost, lower performance version of ATS-34. No free lunch.

Okay, I've heard enough people say that ATS-55 doesn't hold an edge like ATS-34 that it caught my attention long ago. The main reason I haven't changed the Steel FAQ on this point is because neither I, nor anyone else I know of, has done the simple test of identically sharpening two similar knives, one of ATS-34 and one of ATS-55, and seeing how it works. I know in the past that my impressions of edge-holding, cutting performance, etc. didn't really hold up in controlled testing, which is why I'm cautious.

Yes, moly is a carbide former, and ATS-55 should miss it to some extent. Without doing formal tests, just cutting with ATS-55 blades, I'd guess that the difference isn't dramatic.

So, a question here: has anyone done an ATS-34/ATS-55 head-to-head test to see the difference? Is it as big as many people say? Is it more comparable to Gin-1 in edge-holding, or still close to ATS-34?

rdangerer · Apr 26, 2001

This thread is now diverging off the original topic, but what the hay... Phil Wilson is one of the most experienced custom makers in heat treating and building knives out of the CPM 440V, 420V, 10V, 15V, & 3V steels, so I'll delude myself into thinking this post is semi-on topic.

Originally posted by Cliff Stamp:
That is interesting, the last time I talked to Phil about this I got the impression that it was difficult to get 420V over 59 RC if you temper it at all.
-Cliff

I don't think Phil would mind if I posted two of his responses to my queries back in February. Phil has a waiting list. I'm on it now. I have a couple months before I have to decide 420V vs. 10V. As Phil says "Isn't is nice to have a choice like this, I love it..."

Here are two Emails he sent. In the first, I was asking general pro/con question around 420V vs. 10V for a semi-skinner to be used for cleaning game and not abused by chopping/prying. (p.s., wild pigs are notoriously hard on knives...the hide is one thing, but the dirty bristly hair is a serious abrasive...dirt itself will dull a knife VERY rapidly).
~~~~~~~~~~~~~~~~~

From Phil:

"Robert, The best example I can give is based on my own experience. I used a 420v and 10v knive on a pig hunt last July. I got about a 200 meat pig (sow), and a friend got about the same size boar. He used the 420v ( RC 61) knife and was able to do the field dressing, and skinning without touching the blade on a stone. It was what I would call dull when done. I used a 10V (Rc63) for the same operation on the sow and it was still very sharp when done. It would have done another I believe. My pig was a little cleaner than his and maybe a boar is a little tougher, I don't know. . On a recent elk hunt I took a 420v (61) semi skinner. We did field dressing on a cow elk and then the skinning. It was very sharp when done. I couldn't pry the knife out of the guides hand so ended up giving it to him. He called me later and said he has done 3 more elk since without touching the blade. I don't know how sharp it is now but he said he felt he could use it again and would let me know. Cutting rope I can get about 20% to 40% more cuts with 10V over 420V. I guess the only thing this proves is that pigs are tougher on a knife than elk and that a harder blade stays sharp longer.

It is a hard choice but I think I would opt for the 420v cause it does the job and still has the bonus of being corrosion resistant.

My knives are very easy to sharpen so as long as you can do one animal and get back to camp to sharpen at your leisure it doesn't make a big difference I think. I kind of like to sharpen them anyhow.. But its up to you...

Philip C. Wilson"
~~~~~~~~~~~~~~~~~~~~~~~
Then my next note back to Phil:

"Ok, this rings a bell for me. I've read most of the articles you've written for the mags, but didn't review before I typed up the question. (Repetition is the key to my learning....apparently).

I reviewed the alloy chart. CPM10V and 420V are pretty close in terms of alloy makeup EXCEPT for the 5.25% vs. 14% chromium. And backing the chrome out improves toughnes, and so allows you to heat treat the 10V to Rc63 at similar acceptable levels of toughness whereas you stop 420V at Rc61 to achieve similar toughness.

I've read enough of Wayne Goddard's stuff, among others, to know that if all else remains equal, harder knives hold an edge longer in general terms, ignoring toughness for a minute, and ignoring all the Vanadium carbide abrasion resistance issues for a moment.

I don't mind sharpening knives either. I.e. after cleaning an animal or two on a good day or weekend hunting.

So, the question for me to answer in the 10V / 420V question is the corrosion resistance question...is it something I really want or need. Or do I want to stretch the edge holding envelope on this knife.

One more question... I'm guessing that CPM10V is more likely to rust (if not cleaned up thoroughly) at Rc63 than is D2 at 60-61. I'm guessing 10V is less likely to rust than say 52100. And it probably is about like A2 or M2. Fair?

(I've been surprised to find mild surface rust after a month or two in storage on Dozier made (rough 240-320 range grit hollow grind finish, or lack thereof) D2 knives when I thought they were reasonably soap/water clean. May be his rough/economical finish that is the culprit).

I suspect you can get a decent satin finish on 10V, nothing display quality mind you, just a good looking brushed working finish. I should be able to get this reasonably clean, and in any case should plan to lightly oil or TufCloth the blade when done. Fair?
~~~~~~~~~~~~~
Phil replied:

"Robert, you are on target with your observations, a couple of other notes.. 10V has a much higher attainable hardness than 420V. I can get RC 66-67 as quenched whereas about 63 max with 420V. A little chrome aids hardenabiliy and more tends to retard it. On paper 10V is tougher at 63 than 420V is at 60/61. I am playing with a 420v knive at 62 that seems pretty good. It is ground pretty thin, and still seems to be plenty forgiving. It is holding an edge on par with a Rc63 10v blade, looks like. Yes hardness equals edge holding. I am finding that out also. I think it is because the harder edge is stronger and will not roll. This is more important on the CPM's than I thought it would be. The edge has to be hard enough to stand up before the carbides can come into play for wear resistance. I haven't had a rust problem on my 10V hunters yet. I just clean them up and put in a dry sheath. I have a 10V kitchen knife that has some pitting and some black discoloration on it. this is mostly from wet contact with other utensils. Sets up a battery and electro etch condition.

I do get a pretty decent hand rubbed finish on both materials. They act similar in resistance to finish. I am working on this to try to do better, may try some diamond polishing compounds.

Yes finish does affect corrosion and also the grain structure has an effect. The very fine structure in CPM's is positive in that regard, whereas D-2 has a pretty gnarly structure. I have a D-2 made by another maker who tends to rust in the sheath.

One more thing to consider---- I think 10V is a more aggressive cutter than 420V, There is more contrast between the hard carbides and the steel matrix. 10v carbides contrast against mostly iron carbide (relatively soft) where 420v carbides against a lot of chrome carbides ( harder than iron carbide). This is subtle but noticeable... Its still your choice. Isn't is nice to have a choice like this, I love it.. All for now

Philip C. Wilson"

[This message has been edited by rdangerer (edited 04-26-2001).]

[This message has been edited by rdangerer (edited 04-26-2001).]

Jeff Clark · Apr 26, 2001

Here's a comparison that contrasts ATS-34, ATS-55, and some others.

http://www.bladeforums.com/ubb/Forum3/HTML/001863.html

Walt Welch · Apr 26, 2001

FNG can't even keep his alloys straight, asks multipartite question, and gets lengthy and helpful responses from widely known authorities. Only on BFC!!

Walt

Jeff Clark · Apr 26, 2001

If you haven't seen it already, there is a nice article on CATRA testing on the Buck forum.

http://www.bladeforums.com/ubb/Forum27/HTML/000899.html

From my perspective the CATRA tests might be most representative of blade performance on tough abrassive media. Something like a lot of cardboard. The edge geometry effects might not be as significant for cutting more compliant materials like meat or hide.

I'm a long time believer in the 15-degrees-per-side school of sharpening.

Lomic · Apr 27, 2001

Here is the lowdown on CPM Steels. (440V and 420V)

Yes, they are heated to a lower Rockwell Hardness (55-56) than other steel, but NO that does not effect their ability to get a sick edge and hold it there.

I have a Microtech Socom Prototype made with 420V (nearly twice the vanadium of 440V at a whopping 9%). I can tell you first hand that this knife cuts like crazy and holds a razor edge better than any other knife I have ever seen.

How you ask? Well, when CPM Steels are made, the vanadium is actually added in particle form into the layers. Hence the CPM (Crucible Particulate Metalurgy). The end result is this. Although the STEEL may only have a RC or 55-56, those tough little Vanadium Carbides have a Rockwell of 80-85!

It is actually the Vanadium Carbides that do the cutting and hold the edge, while the rest of the steel just gives it strength and holds things together.

So trust me on this one, these steels hold an AMAZING edge for a good long time, but they are a bitch to sharpen.

If you can still find one (there were 15 made I think) Pick up a Microtech SOCOM Elite s90v (same as 420V) prototype. Should cost you about $400.

Otherwise, you may try the Spyderco Military made with 440V for only $119 (a really good value). knifecenter has them in stock
http://store.knifecenter.com/pgi-ProductSpec?SP36GPE

By the way, spyderco has some really good steel info on their site, as does Crucible Steel.

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Marc

RJ Martin · Apr 27, 2001

Guys: I didn't read the whole post, but, here are my comments based on my experience:
BG42 is superior to ATS34, in both composition, method of manufacture and field performance. Yes, You can achieve RC64-this is generally the As Quenched hardness if an ideal cycle has been performed. However, that is not my recommended working hardness. Depending on edge thickness, 60-62 is reasonable. 60/61 is my target. Hardness is not the "end all" for steel performance0-control of microstructure is. As stated in one of the responses, the Vanadium in BG42 is doing some great things for you-boosting the strength/toughness through grain refinement and adding the fine, hard Vanadium carbides.
As to 440V, I have not experienced brittleness at hardnesses up to RC58.
Again, slightly lower hardnesses can produce a very serviceable blade, because of the V.
M2 is designed to make tools to cut other steels, although many cutters are made from M42, it's "brother".
Being a true High Speed Steel, the heat treatment required for M2 is HIGHLY dependant on PRECISE time/temperature control, and, therefore the finished product is affected more severly by process variation. I'm talking about just a few minutes time or a few degrees here-not much margin for error!!

You also need to factor blade/edge geometry-it's not just about the steel, or even the heat treat. Brittleness at the edge is very dependent on thickness and edge geometry.

Hope this helps,

RJ Martin

Lomic · Apr 27, 2001

PS -- Jeremy, give my last post a quick read, and then go pick up that Spyderco Native. I personally prefer the Military for the liner lock and size, but that native gives you a great edge at a great price.

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Marc

Samurai6 · Apr 28, 2001

I believe in what Cliff said about steel being important in terms of edge durability and all that, I have just not been able to demonstrate it to myself. I wondered about all this one day so took an O-1 Mad Dog, a 52100 Alan Blade, a CPM 420V Straight Krait, an A-2 Black Cloud, and several different ATS-34 knives to the garage for some destructive edge testing. I chopped and pounded all the blades through coat hanger wire. They were all sharpened similarly except two, a Gerber Covert, and the Straight Krait. Coincedentally, the Krait and the Covert were the only blades that suffered no damage at all. Why? Because they were the only ones that still had the factory edge that was sharpened at close to 50 degrees included. I could figure out why an ATS-34 REKAT Pioneer would lose a chip the size of a pin head while the Covert went undamaged, so I resharpened the edge of the Pioneer at a steeper angle, around 40 degrees, and miraculously, it was then able to go through the wire without fracturing.

I know steel types make a difference. The difference in toughness between the Benchmade M-2 AFCK and the ATS-34 AFCK was very obvious when you bury the tip in a board and pry it out sideways. The tip on the ATS blade snaps much more readily. But the tip on the M-2 knife snaps eventually.

My conclusion for a newbie considering knives of many different steel types: buy them all, they are probably great knives with unique characters. The edge geometry makes much more difference in edge durability than any other factor...in my experience, to the point where, as long as you are talking about high carbon, low alloy cutlery steel, steel type is of no consequence when compared to ergonomic design and edge shape.

ATS-34, if heat treated in the right ballpark, generally makes a great knife blade, and the CPM steels, BG-42, 52100, M-2 all just go up in potential performance from there. It is just good and gooder.

rdangerer · Apr 27, 2001

Originally posted by rj martin:
Hardness is not the "end all" for steel performance - control of microstructure is.
RJ Martin

Good post by a maker who cares about heat treat.

RJ, if you come back to peruse this thread ... I'd be interested in a few sentences of elaboration on your point above.

Control of microstructure... I believe you are talking about grain refinement here.

Where in the heat treat does grain structure go "right" or "wrong"?

Can you recommend an authoritative book on heat treating ... and/or a book that covers the modern steels we see used for knives... ATS-34/BG-42/D2?

Given identically hard blades via Rockwell tester, does a finer grain structure:
1. result in a tougher blade?
2. result in a blade that is easier to sharpen?
3. result in a blade that'll take a more (subjectively) wickedly sharp edge?
4. result in a blade that takes a more or less grabby/toothy edge?