Requesting objective ranking of steel qualities

I know the basic qualities of various blade steels, But I (and probably many others) want to know specifically how different steels compare to each other. Objectivity is a must IMO. For example, toughness of M2 gets a score of 9, ATS 34 scores a 7. Qualities that I am interested in would be toughness, abrasian resistance, ease of sharpening, hardness, edge retention, rust resistance, and value. When I say value, I mean bang for your buck. For example, it seems to me that 440c and ATS-34 are both excellent all-around steels. ATS-34 being harder and more abrasian resistant, but 440c being tougher and more stainless. But it seems for such similar quality steels, ATS-34 is quite a bit more expensive, therefore, more bang for your buck with 440c. I have read Joe Talmadge's (sp?) article on steels at Bladeart.com, and it is excellent, but I would like to know specifically how steels compare to each other. Steels I am specifically interested in are: ATS 34, CPM 440v, BG-42, ATS-55, 154CM, VG 10, GIN-1, D2, 440C, and M2. Feel free to add other steels you believe are worth considering.
I realize heat treat is also a very important factor. It would be great to know, for example, the hardness and toughness differences between HRC 55 and 57 of CPM 440v. Oh, and one other thing, what does RKBA stand for? Thanks in advance for any replies. Nail_dude
 
Right to Keep and Bear Arms.

Heat treatment and intended use have so much to do with steel that the term objective almost has no meaning.

I have a BG42 short sword in process.

As I did my research on steels, Timken-LaTrobe, the manufacturer of BG-42, very kindly sent me a huge amount of data, some of it comparing ATS34 and 440C to BG42.
I noted with surprise that in some applications and with proper heat treatment, that the simpler and less expensive ATS34 and 440C compared very favorably to BG42.
440C especially demonstrated a lot more toughness than I would have expected.

Even if a person decides that BG42 has some slight advantage over ATS34 and 440C, he must also consider the difficulties associated with heat treating BG42.
I know of only four people who heat treat BG42, (Chris Reeve, Gene Osborn, Paul Bos and Thomas Haslinger) and only two of them (Paul Bos and Thomas Haslinger) will take outside maker's knives.

Then, when a person starts talking toughness, what do they mean?
How does one measure toughness?
Steels with sheer resistance to abuse in my mind include O1 and L6, but some of the sword and kukri people will argue for one of the simple low chrome or unalloyed steels.

Some of the makers who specialize in Japanese type of hard use blades prefer a much lower carbon steel than one might otherwise associate with cutlery, and, with extreme attention to heat treatment they produce blades with remarkably hard edges and almost elastic, resilient spines.
Some of them use cable out of the scrap heap and yet they charge many thousands of dollars for their blades.

For myself, I make the distinction between stainless and non-stainless, and, after that, I trust the maker to use the steel he knows best.

Greco uses A2, Randall uses O1, and the Nepalese Kami's use automobile leaf springs.
Good enough for me.

However, since I place a high priority on corrosion resistance, I have chosen BG42 for my blade.
Of all the stainless types of steels, I think it combines the best qualities for a short sword.
In a smaller blade I would have gone with D2.
I hope the perceived (not necessarily real) advantages of B42 justify the hassles and expense.

Remember, in all these high tech, trick stainless steels, one winds up with an alloy containing barely 75% iron.
What does that mean?
Something good?
Something bad?

Aside: does anyone have experience with or access to W2?

------------------
Luke 22:36, John 18:6-11, Freedom
If one takes care of the means, the end will take care of itself.
 
You already know quite a bit. But not quite enough to realize that it is Impossible to answer your question.

Even if limit your question one parameter, say abrasion resistance, it would be hard to find an objective way to evaluate different knives. There are just too many variables. Heat treatment is the critical thing. It is also quite invisible.

All of the steels you mention are good knife steels. You did not list 420V (now called S90V), this steel is regarded by many as probably the best stainless steel around. But if stainlessness is not a concern, there are many relatively simple carbon steels which may outperform it in some respects.

There is no Best steel. Any ranking of steels will necessarily be flawed or suspect, and probably will not be all that objective. For example, do you give equal weight to edge retention and stainlessness? A lot of folks would like to see an objective ranking of steels, but it is simply too complicated a question. All steel alloys seek to balance sometimes conflicting physical properties. That is where heat treatment plays the largest role.

I like 420V for a stainless knife, and 52100 for a non-stainless knife. But ATS34/154CM are good knife steels as well and BG42 may have a better all around performance index than either of thosese. D2 is also a superior blade steel for small knives. These are all very different materials, and depending on the size, geometry, and intended function, you might choose any of them. It is not an error of ommission that Joe failed to rank order the steels he describes. You can not objectively and correctly answer the question you ask.

There is no BEST steel.

Ken, W2 is great stuff. Takes a wicked edge, is easy to sharpen, and is tough. A lot of older files are W2. The car leaf springs mentioned are probably 5160.

Paracelsus

[This message has been edited by Paracelsus (edited 06-02-2001).]
 
N

Nail_dude

Joined
Apr 26, 2001
Messages
7
Sorry Paracelsus if I was a bit confusing in my post. What I want to know is how specific qualities of steels compare to each other. I think that one can be objective in this regard. It is safe to say that BG-42 is harder than 440A. If you just want a hard steel, then BG-42 would be preferable. These are the sort of comparisons I am looking for. For example, you hear that both M2 and CPM440V hold an edge really well, but which would hold an edge longer on the same knife? I will be the first to agree with you that there is no "best" steel. As I heard Sal Glesser say in many of his posts, all good just different.

 
Nail Dude,

As one "newbie" to another, I think your question was perfectly clear and sensible---you are seeking relational values. I suspect that the longer we visit here, the less will be our ability to give straightforward logical answers. This placew is really a law school
smile.gif


Honestly i understnd comments like "it is impossible to be perfecly accurate" as there is spectrum of variable factors such as heat treatment, acuteness of grind, etc . Still these answers can be frustrating for "newbies" like Nail dude and me not because we are ignorant (maybe-maybe not ) but because answer like "thou shalt not make objective statements about steeles " appears to represent the voice of "political correct " ideology here.

For paralell look to sports like basketball. Ok, Allen Iverson is high scorer but has fairly low shooting percentage ,especially in playoffs something like 28 point/38% shhoting average. Kobe bryant of the Lakers has slightly higer point average ( maybe 30-31) and higher shooting % like 48%. Comparing Iverson and Kobe is not completely fair, kobe is bigger man and plays with help of Shaq O'Neill and Iverson is primary playmaker who is responsible for riskier plays. OK, every basketball fan knows that players qualities are not reducible to statistics ,you cannot simply say Kobe is better because his numbers are better. But knowing statistic like point per game, shooting % , rebounds, assists, steals, minutes played, even how he scores in 4th quarter vs first is still useful information for comparison, if if it is'nt "fully objective" or "whole picture ".

Asking for some kind of scale like Nail Dude seeks is not same to asking "what is best steel?" (or who is best basketball player) We know it doesn't give "truth" but guideline. Those numbers can help us understand that Kobe Bryant is more reliable in 4th quarter than Shaq usually. but does that mean in every game against every team, no of course not. But it gives us guidelines for comparing steels in general sense .

Besides ,if you can't give us these guidelines to help us answer our own questions, we might keep asking specific question like "what is best steel for stabbing a sentry thrugh a brick wall in corrosive, tropical region"?
smile.gif


respectfully,
Martin
 
Nail_dude, I think I understand what you're looking for. The following is my impression of different steels from what I've read and remember. I am NOT an expert, and probably have some of my info wrong (please feel free to correct me, guys). But, it may be of some use. I'll omit info that I don't feel too confident in putting down. Also, the qualities of a steel depends HIGHLY on the heat treat, and I'm ranking the steels upon what I consider their average heat treat. Here's how the rating system works: a "10" indicates the highest (or one of the highest)toughness among the steels LISTED (not all steels). A one indicates the lowest (or one of the lowest) in the steels listed. BTW, ATS-34 and 154-cm are practically identical. I doubt my proportions are right. I'm mainly trying to "grade" the steels in order to compare them.

Toughness
CPM 440v ---5
BG-42
ATS-55 ---6
154CM/ATS 34 ---6
VG 10 ---7
GIN-1
D2 ---7
440C ---6
M2 ---8
52100 ---8
5160 ---10

Edge Holding
CPM 440v ---10
BG-42 ---8.5
ATS-55 ---7
154CM/ATS 34 ---8
VG 10 ---7.5
GIN-1 ---7.5
D2 --- 9
440C ---7
M2 ---9
52100 ---10
5160 ---9


Corrosion Resistance
CPM 440v ---10 (not too sure)
BG-42 ---8
ATS-55 ---8
154CM/ATS 34 ---8
VG 10 ---8
GIN-1 ---10
D2 ---6
440C ---9
M2 ---1
52100 ---1
5160 ---1


Ease of Sharpening
CPM 440v ---2
BG-42
ATS-55
154CM/ATS 34
VG 10
GIN-1
D2 ---4
440C
M2 ---9
52100 ---9
5160 ---10

The I don't know much about the rest of the steel qualities.

Hope that helps.

[This message has been edited by Andrew Lynch (edited 06-02-2001).]
 
I understand your question just fine. But I still can not answer it. The example of 440A is a good starting point. It has a low carbon content and simply will not get as hard as BG42. On the other hand, BG42 could be heat-treated in such a way as to be much softer than fully hardened 440A and be an inferior knife blade.

The optimal heat treatment for different steels is very different and subject to individual preferences. 440V as often heat-treated holds an edge longer that 440C, but may be much more brittle. Some manufacturers have been lowering the hardness of 440V to bring back some toughness, but at a lower RC some of the abrasion resistance is lost. So it is not so clear that 440V is superior to 440C. The heat-treatment changes the physical properties of the steel so much that it is not enough to simply say that this steel is better than that steel. Even the 'optimal' heat-treatment is subjective and influenced the size and purpose of the knife.

I have opinions about which steels make better blades than others, but if I make choices, they will be based on my Subjective impressions. I agree with Ken about choosing between stainless steel and carbon (low chromium) steels First.

If rust resistance is not important, then many carbon steels could be considered superior to most stainless steels. 420V may be the long exception, IMO. I simply prefer the working properties, edge retention, and ease of sharpening of the 'carbon' steels (they are better called low chromium steels). The addition of high concentrations of chromium has a deleterious effect on the steel. The way 420V is made gets around some of the limitations of high chromium concentrations.

So for stainless steels, considering edge holding only, I would order steels something like this: 420V ------> D2 -> BG42 -> VG10 --->ATS34/154CM ---> 440C

One the other hand, I have knives made from each of these materials and I like them all.

The main point to be made is that ALL of these steels will make fine knife blades. If you are a very competant knife sharpener, the best steel that is a compromise between edge holding, ease of sharpening, and tougness. Depending on the blade application, some steels are better choices than others.

There is no rule that says 'thou shall not make objective statements about steels'. I understand how comforting this might be, but it is impossible. There are many here who understand that such a list denies the complexity of the issue, and any rank ordered list will be subject to Subjective parameters.

Because the physical properties of any steel are determined by the heat-treatment, it is not enough to simply say this alloy is better than that alloy. It is not political correctness, it is just wisdom.

A couple of years ago, a newbie who had gotten the impression that the 'best' steel was 440V attacked a famous maker for having the audacity to use 440C for his blades. This new guy actually believed that this maker was ripping his customers off by using a cheaper and 'inferior' steel. This sort of misunderstanding is why I and others decline to rank order steels. It is a mistake, is not objective, and gives folks wrong ideas.

Paracelsus, trying to be clear about a murky topic
 
Not being too sharp on my steel knowledge, I'll ask a question here. Does the heat treat effect corrosion resistance? If not, could somebody list a bunch of steels in order of corrosion resistance, assuming something simple like a satin finish? It's a big factor for me.
 
Martin,
Do you really think we're PC here? There is a wealth of information about blade steels available by using the search function. The question that was asked has no easy answer. A lot has to do with the application and, as has been previously stated, heat treatment.There are so many variables that any sort of matrix to rate each would be very difficult. It is not a matter of being afraid to rate them top to bottom on each variable.
Right now there are so many good options, the choice has gotten harder, not easier. That is why "old-bies" keep harping on using the search function.It is a matter of sifting through the existing information to make the best determination for the individual.
David

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AKTI# A000150
NC Custom Knifemakers Guild member
NC Knife Knuts member
 
Wear resistance and toughness are objectively quantifiable qualities, and test protocols exist for each. Attempting to reinvent the wheel by posing a different, subjective evaluation system is of dubious value.

Crucible explains wear resistance and toughness, and how each contribute to various tool steels HERE

I also suggest you use the SEARCH feature.

Just remember, there isn't any magic alloy, just as there is no silver bullet.

Walt

[This message has been edited by Walt Welch (edited 06-02-2001).]
 
<font face="Verdana, Arial" size="2">Originally posted by Buzzbait:
Not being too sharp on my steel knowledge, I'll ask a question here. Does the heat treat effect corrosion resistance? If not, could somebody list a bunch of steels in order of corrosion resistance, assuming something simple like a satin finish? It's a big factor for me.</font>
Click to expand...

Heat treat affects every quality being discussed here, which is one reason why I feel any "objective" list can easily be quibbled with.

In the case of corrosion resistance, the biggest determiner of that in a particular steel is the amount of free chromium -- that is, chromium that is not tied up as carbides -- in the matrix. Different heat treats can leave relatively more or less chromium as carbides. More as carbides will probably mean better wear resistance; less as carbides will probably mean better corrsion resistance. Changes in heat treat of ATS-34 can definitely change the corrosion resistance. And, further complicating things for ATS-34, there are actually two different heat treat curves that are said to yield very different results.

Walter correctly shows that there are objective tests and measures for things like toughness and strength. However, again, it's a matter of the heat treat of the steels being tested. My personal experience has been that given a particular kind of steel, the difference in performance from an average heat-treater and an extraordinary heat-treater can be enormous. I'm sure Crucible's numbers are right for the steels Crucible heat-treated and tested. But what if Walter Brend had heat-treated the ATS-34? Now what if Ernie Mayer had done it? What if Dozier heat-treated the D-2?

I continue to believe that if you seek to compile some objective list that is always accurate, you will be guaranteed to be led astray at some point or other. These lists are useful for beginners, as long as they're considered a marginally accurate starting point in the study of steels. If you're not really into knives, then a well-done list might be good enough for you, and hopefully keep you from making a really bad decision, although sometimes they'll be a little off. Otherwise, as you learn more, you'll realize that due to the variables involved, steel knowledge can be more complex, and things you "knew" about steels turn out to only hold under certain conditions.

Joe



[This message has been edited by Joe Talmadge (edited 06-02-2001).]
 
<font face="Verdana, Arial" size="2">Originally posted by Nail_dude:
Sorry Paracelsus if I was a bit confusing in my post. What I want to know is how specific qualities of steels compare to each other. I think that one can be objective in this regard. It is safe to say that BG-42 is harder than 440A. If you just want a hard steel, then BG-42 would be preferable. These are the sort of comparisons I am looking for. For example, you hear that both M2 and CPM440V hold an edge really well, but which would hold an edge longer on the same knife? I will be the first to agree with you that there is no "best" steel. As I heard Sal Glesser say in many of his posts, all good just different.
</font>
Click to expand...

Well, there are some other interesting variables, right? First, keep in mind, BG-42 is not, as you state, harder than 440-A. BG-42 is more hardenable, but it's not clear that every BG-42 blade in every knife has been left by the heat treater harder than every 440-A blade.

The M-2 vs 440-V discussion is another interesting one. At, say, 60 Rc, we would probably expect 440V to be more wear resistant. But, what if you want high cutting performance in your blade? In that case, you'll want to sharpen the edge very thin -- 15 degrees per side, or even less. At 60 Rc, M-2 will be able to take some pretty rough treatment, even with a 30-degree (total) edge. Start working your 440V knife hard, and I think you'll see it chip out, and quick. So, 440V may be more wear resistant at a given hardness. But since edge holding is the term you specifically asked about, and since wear resistance is only one factor in edge holding (another factor being, for example, whether the steel is tough enough to not chip out at the edge angle you've chosen to do the particular job you want), you could be led astray very quickly by naively assuming wear resistance always equals edge holding.

Again, I think we can take a reasonable shot at a list that may not guide you to the best steel every time, but will guide you to mediocre-at-worst, and that's not bad. But to make a really good choice, you'll want to understand more, like the interactions between wear resistance, toughness, and strength; the performance requirements, and edge angles and finishing grits required to meet them; the profound differences in performance that excellent heat treat can cause.

So, as long as you understand that armed with the list alone, you'll end up with mediocre-at-worst decisions (but not always better-than-mediocre), it's worth pursuing the list.

Joe

 
<font face="Verdana, Arial" size="2">I know of only four people who heat treat BG42, (Chris Reeve, Gene Osborn, Paul Bos and Thomas Haslinger) and only two of them (Paul Bos and Thomas Haslinger) will take outside maker's knives.</font>
Click to expand...

I think Rob Simonich does his own and others knives. And Kit Carson? Someone else does his heat treat? I don't know. I would be surprised.


Steve-O
 
Kit does his own heat treating.

He is moderately successful at it. The reason he likes Talonite (r) and Stellite (r) so much is that he doesn't have to heat treat them (laughing, ducking, running for cover).
wink.gif


Walt
 
To give you an illustration of how difficult achieving the best possible heat treat for a particular steel, you might want to spend $15 and buy Ed Fowler's book, "Knife Talk."

Ed is one of the most serious students of steel, and how to maximize it's performance. I assume that many of his master smith brethren and sistren (why have I never heard that word before?) join him in the quest for the perfect steel -- forged.

For years, Ed has worked primarily with 2 steels -- 5160 and 52100. By constant testing -- to destruction -- and by experimentation, he learned how to make truly high performance blades of both steels. Since they're high carbon, no/low chormium, they have little resistance to corrosion. But, as the chart provided earlier in the thread, they both rate very high numbers in the other abilities sought.

Ed added cryogenic treatment, after proving to himself that it dramatically increased the performance of his steels. He normalizes, anneals, triple hardens with triple quenches, deep freezes, then triple tempers his blades. They'll all bend 90 degrees without breaking. All have their edges tested severely for chipping. They take a good edge and hold it very well. They resharpen extremely easily. So, both are very good steels after Ed has worked his wonders. Someone else, who might not view the requiremetns to pass the Master Smith exam as minimum standards, is likely not to do as good a job with those 2 steels.

Wayne Goddard, in a Blade column, said he found D2 extremely difficult to make cut. He acknowledged that Bob Dozier has the ability to make extremely good blades from D2.

In summary, a bright man, extremely serious about reaching the upper limits of performance from 2 steels has spent around a quarter of a century getting to the level of ability to make them consistently high performance. Yet, he says at least once in his book that he has far more questions than answers about steel. It is truly impossible to provide the "objective" comparison you requested.

------------------
Asi es la vida

Bugs
 
Nail_dude:

[toughness]

<font face="Verdana, Arial" size="2">HRC 55 and 57 of CPM 440v</font>
Click to expand...

Hardness : Impact toughness (ft-lbs)

56 : 16
59 : 12
60 : 11

There is a wealth of information on such properties for all steels including cutlery steels. Bill Bryson has written "Heat treatment, Selection, and Application of Tool Steels", which contains impact toughness, wear resistance, machinability, and hot hardness. Crucible has such information for thier steels (which is where the above comes from), and of course there are lots of materials texts.

And yes of course heat treatment effects the answer this doesn't make the question unanswerable, you just have to be specific about the heat treat in the reply. For example ATS-34 annealed is tougher than 440A hardened. However if you heat treat ATS-34 to take advantage of its higher wear resistance and hardness, 440A will have a higher toughness, ductility and corrosion resistance while ATS-34 will have a higher strength, wear resistance, hot hardness, and compression resistance.

Or consider :

Steel : Hardness : Impact toughness

440C : 56 : 26
D2 : 59 : 21

You can see that D2 is tougher than 440V even when 440V is softened by 3 points. And that 440C is tougher by over 50% at the same hardness. You would want to specific the hardening and tempering temperatures as well as the frequency of tempering and if cryo was used or not and if so how, for a complete picture.

-Cliff

 
Uh Cliff, I think you just made a very good case for what Joe, myself, and others have been trying to say. Although it is correct that objective tests can be performed, for an particular alloy, lots of information about heat-treatment will be required to make data meaningful. The information required to compare two different alloys for suitability as a knife blade becomes even more complex.

Many new guys base their impression of various steel types on experience with different knives that may have been heat-treated in very different manners. Add the problem of normalizing geometry and you have a terribly complex matrix which becomes almost impossible to properly control for experimental bias.

So yes, I agree that in principle an objective rating system is possible, but in reality, any list that ranks orders steels will be confusing at best. For example, how do you properly weight toughness compared to wear resistance? Ultimately, a maker will balance these physical properties in a somewhat Subjective manner by choosing steel and heat treatments based on the size and purpose of the blade. Fortunately, human beings can be pretty good at subjective assesments.

[This message has been edited by Paracelsus (edited 06-04-2001).]
 
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