Hardness vs Wear Resistance?

[Ankerson]

They might be close you're right. But even if I did achieve the same results as you it doesn't prove anything because my set up would have all the same variables as yours. I can not sharpen a knife exactly the same as you, I can not apply force at the same acceleration as you, I can not use rope with exactly the same make-up as you, etc.

I know, that's why I say my results are not the end all beat all results.

It's what works best for me and it's accurate for me doing it the way I am.

I am not the only one doing it this way either by the way and our results are comparable.

 

[Ultimate]

I know, that's why I say my results are not the end all beat all results.

It's what works best for me and it's accurate for me doing it the way I am.

I am not the only one doing it this way either by the way and our results are comparable.

I know, I understand that. But reading some of your previous posts I got the impression that you thought your results were 100% accurate, which they are not.

 

[singularity35]

They might be close you're right. But even if I did achieve the same results as you it doesn't prove anything because my set up would have all the same variables as yours. I can not sharpen a knife exactly the same as you, I can not apply force at the same acceleration as you, I can not use rope with exactly the same make-up as you, etc.

It would indicate that the steels within Ankerson's categories do have similar edge holding and wear resistant properties. Ankerson's results seem to parallel real world experiences by people using these steels.

 

[Ultimate]

It indicate that the steels within Ankerson's categories do have similar edge holding and wear resistant properties. Ankerson's results seem to parallel real world experiences by people using these steels.

No, it indicates that by chance, I got the same result as Ankerson. It does NOTHING to validate any claim made about wear resistance/sharpness or whatever you are testing. Even if Ankerson and I reproduced experiments accounting for 99.99% of the variables, it wouldn't matter; simply because 440A in one knife is not the same as 440A in another knife. It will NEVER be. Therefore, you can not say "440A has these qualities and exhibits this performance". You can not, with 100% accuracy, group knives into categories and take it as fact. Like I said, it may work for you, but it is not fact and does not really prove anything.

 

[Ankerson]

I know, I understand that. But reading your previous posts (between you and Vas) I got the impression that you thought your results were 100% accurate, which they are not.

Not even CARTA is 100% accurate.

I am not ranking the steels in order, Vas is.....

I wouldn't even attempt to even try to rank them in order doing it by hand.

My results are accurate for what I am testing for within the variables I have set. I set margins of error and I stay within those as was laid out in my thread.

Any more that that is for the Lab guys in the white coats with Multi Million dollar budgets

 

[Ultimate]

Not even CARTA is 100% accurate.

I am not ranking the steels in order, Vas is.....

I wouldn't even attempt to even try to rank them in order doing it by hand.

My results are accurate for what I am testing for within the variables I have set. I set margins of error and I stay within those as was laid out in my thread.

I never said they were 100% accurate. No one is 100% accurate, that is basically my point.

But anyway, I would still love to see your experiment set-up and maybe the raw data if you wouldn't mind. (I am not being sarcastic, I really would like to see it)

 

[singularity35]

No, it indicates that by chance, I got the same result as Ankerson. It does NOTHING to validate any claim made about wear resistance/sharpness or whatever you are testing. Even if Ankerson and I reproduced experiments accounting for 99.99% of the variables, it wouldn't matter; simply because 440A in one knife is not the same as 440A in another knife. It will NEVER be. Therefore, you can not say "440A has these qualities and exhibits this performance". You can not, with 100% accuracy, group knives into categories and take it as fact. Like I said, it may work for you, but it is not fact and does not really prove anything.

I'll take 95 percent accuracy.

I'll take real world experience by a few credible users who know what they are about over nothing. Which is the alternative.

As of the moment there are no other results besides Vas's.

 

[Ultimate]

I'l take 95 percent accuracy.

Like I said before, I got the impression that Ankerson thought his results were completely accurate. You can get close, but never 100%.

 

[Ankerson]

I never said they were 100% accurate. No one is 100% accurate, that is basically my point.

But anyway, I would still love to see your experiment set-up and maybe the raw data if you wouldn't mind. (I am not being sarcastic, I really would like to see it)

My raw data will never be released to the public, not for free anyway. Way too much work and expense to give it away.

My setup is simple as I said before, it's a scale, a piece of wood and rope. I sharpen on the Edge Pro. The Blades are RC tested after I cut with them.

It's very basic and simple. :thumbup:

If you use the same setup as I do and start cutting you will start to see categories develop just like I did after awhile once you have enough steels tested.

I am sure the data cut for cut won't be the same as mine, but that would be your data and categories based on your testing.

You will see patterns develop, and repeatable patterns.

And it possible that your categories could be right in line with mine in the end, or very close.

It's the end results that are important.

 

[Ankerson]

Rockwell testing is extremely important, it's a must, has to happen when comparing the same steel as they will be different if the hardness is different between the blades.

Sharpening all the blades the same way to the same angle is extremely important, why I use the EP and polish all the edges to the same sharpness. As close as I can get them and testing the level of sharpness as was laid out.

The blades should be close as possible to the same, thickness behind the edge has to be close.

All the blades must start out at 14 to 15 LBS of down force, 15 LBS is the MAX starting pressure. That's also the reason the blades have to be close, the starting down force confirms that.

I test to 20 LBS of down force.

That is my standard, the criteria that I set to cut down the variables.

 

[Razorsharp1986]

It is very interesting to see so many people are preoccupied with blade steels and such. I honestly don't get the fascination from testing all these random steels. If I've had a blade made of good old 1095, in my use, outperforming S90V, then for me it would be the better steel. Even if a reputable member like Jim tested it and it "scored" way less than the S90V or even a lower end steel.
You use what works best for you, simple as that. Many knives, with same steels, perform differently at times. People should never disregard factors such as hardness, geometry, and sharpening skills. Which all influence edge holding. Also, if when cutting you start applying sideways strain on the edge, the edge now encounters a different force and will probably exhibit different edge deformation, thus different edge retention results.

 

[Phil Wilson]

ans7812.
I understand where you are coming from. You obviously have a tech back ground and a very curious nature. Here are some things to consider. We all cut and test for different reasons. I started cutting rope as an indication of the "cutting efficiency" of my knives. This is a method started by Wayne Goddard and one of his hunter testers. Wayne passed it on to me and I passed it on to Jim. I say cutting efficiency since all the factors you mentioned come into play and influence the way a knife, not a steel cuts. It is not precise, never can be as you noted but it does show if larger differences in how a knife cuts. I compare notes with Jim and even though I cut 3/4 rope now. If we look at percentage differences we compare very closely. I got him into this method since some of the results I was getting needed to be confirmed by someone independent of my self. Vasili said it -- some times you get exactly the results you want. I do have a hardness tester, do my own heat treating, and have been messing with this testing for more than 20 years now. In addition I have been able to compare my results with some CATRA testing and it amazed me that tests correlated closely. Why don't I build a machine to test with? I have a pretty complete shop with lathe, mill welding equip and the back ground to do it. Because it is just too damn much fun to cut with my own hand. Feel how the knife bites the rope, resharpen for different results, mess around with different handle configurations, blade lengths, belly radius. My tests and results I think are credible,, tell me what I want to know and give me an excellent feel on how my knives are going to preform in the field. Jim's rankings agree with mine except for one particular steel and we are discussing that one now. I don't think you and others would question the fact that CPM S90V at RC 60 would cut better and longer than CPM S30V in almost the exact same knife configuration. That's all he is really saying. I just think rather than questioning all the details look at the end results and take the information for what it is worth. It is up for all to see and it is free at this point. The other thing is take your bath room scale put a piece of wood on it, slot or not, buy a piece of rope and do some cutting. It will amaze you how right away you can tell the differences in knives. Some will not even make one cut on the rope, Others will do hundreds and blow you away. I won't put up any data, I tried that a few years ago and spent too much here on the forums, pretty much the same as Jim is doing now. My time is better spent in the shop making knives. Phil

 

[Ultimate]

ans7812.
I understand where you are coming from. You obviously have a tech back ground and a very curious nature. Here are some things to consider. We all cut and test for different reasons. I started cutting rope as an indication of the "cutting efficiency" of my knives. This is a method started by Wayne Goddard and one of his hunter testers. Wayne passed it on to me and I passed it on to Jim. I say cutting efficiency since all the factors you mentioned come into play and influence the way a knife, not a steel cuts. It is not precise, never can be as you noted but it does show if larger differences in how a knife cuts. I compare notes with Jim and even though I cut 3/4 rope now. If we look at percentage differences we compare very closely. I got him into this method since some of the results I was getting needed to be confirmed by someone independent of my self. Vasili said it -- some times you get exactly the results you want. I do have a hardness tester, do my own heat treating, and have been messing with this testing for more than 20 years now. In addition I have been able to compare my results with some CATRA testing and it amazed me that tests correlated closely. Why don't I build a machine to test with? I have a pretty complete shop with lathe, mill welding equip and the back ground to do it. Because it is just too damn much fun to cut with my own hand. Feel how the knife bites the rope, resharpen for different results, mess around with different handle configurations, blade lengths, belly radius. My tests and results I think are credible,, tell me what I want to know and give me an excellent feel on how my knives are going to preform in the field. Jim's rankings agree with mine except for one particular steel and we are discussing that one now. I don't think you and others would question the fact that CPM S90V at RC 60 would cut better and longer than CPM S30V in almost the exact same knife configuration. That's all he is really saying. I just think rather than questioning all the details look at the end results and take the information for what it is worth. It is up for all to see and it is free at this point. The other thing is take your bath room scale put a piece of wood on it, slot or not, buy a piece of rope and do some cutting. It will amaze you how right away you can tell the differences in knives. Some will not even make one cut on the rope, Others will do hundreds and blow you away. I won't put up any data, I tried that a few years ago and spent too much here on the forums, pretty much the same as Jim is doing now. My time is better spent in the shop making knives. Phil

I understand what you're saying. There is no doubt you will see differences when performing the tests you recommended above. I'm just concerned with someone saying that the tests they've done and results they've acquired completely define the characteristics of a steel (which Ankerson clarified by saying he is just noticing differences between steels).

Steels are extremely interesting because they have so many possibilities, but for practical purposes (like the poster before you said), I don't think it's worth it to try to figure out exactly what's going on (unless you just enjoy it, which I completely understand) because the chances of you receiving two S30V, S90V, 154CM, etc. knives that are exactly the same are pretty slim.

 

[hardheart]

All please keep in mind that the largest difference here is the tests themselves. Even if the testers were to exchange equipment, attempt to mimic the other's procedure and sharpening, and report environmental conditions for each test - the two test procedures themselves are completely different. If Vassili started cutting on a scale, and Ankerson started cutting thread at regular intervals, their results still don't correspond to the results of each of their original tests.

When during the course of his testing does Vassili reach 20 lbs of force to cut through the rope? When is there contact with wood? I agree that since all of Ankerson's cutting involves wood contact that it does not compromise the results - but what it does is makes the test that much more differentiated from Vassili's. When does Ankerson push cut through thread? When does he stop at a predetermined number of rope cuts? They are doing two completely different things with their knives, the only thing in common is that they are using some type of manila rope. For Vassili, it doesn't matter how much force it takes to cut the rope, while that is the performance measure Ankerson grades on. For Ankerson, it doesn't matter how well the edge push cuts thread, while this force is what Vassili grades from.

They would probably have to combine the tests to possibly make a meaningful comparison. Cut the same size rope under as similar as possible conditions, measuring the push cutting force on the same thread with the same scale at the same intervals, while also tracking the force needed to cut the rope on the same scale as well. Push cutting sharpness up to 200 cuts and total number of cuts up to 20 lbs of force would need to both be recorded. The same sharpening system would need to be used, to the same finish and angle, with the same measured sharpness at the start of each test.

That is if you want to compare the tests. They are fine as they are for looking at independently, but you cannot say one is better than the other, since they are different things. Variability exists in both, and it makes repeatable results difficult for a very high level of precision.

Now, for me an issue has always been just how finely must we differentiate the steels themselves? If you control as best you can all the factors you can think of, and the steels score so closely that a change in the weather reverses the ranking - then does it matter that much at that point? I think that you are then dealing with steels too close to bother with worrying about terminal performance differences. Availability, cost, and other factors outside of edge life then become even more important in deciding. Vassili makes very definite decisions about what steel is superior, but many of them are terribly close in measured force, and they aren't tested/evaluated for other factors. Ankerson chooses not to disclose raw data, so we don't know just how different the steels are. He has also told us that the same alloy can more than double the performance by being used in a different knife (geometry and heat treat) They are doing a lot of work, and providing results to the community-but I don't think the results should be used to criticize others. Nothing is perfect, but there is a lot of effort put forth.

It is very difficult (well, impossible) to precisely evaluate alloying when you are actually evaluating a lot more than that all at the same time.

 

[Ankerson]

I understand what you're saying. There is no doubt you will see differences when performing the tests you recommended above. I'm just concerned with someone saying that the tests they've done and results they've acquired completely define the characteristics of a steel (which Ankerson clarified by saying he is just noticing differences between steels).

Steels are extremely interesting because they have so many possibilities, but for practical purposes (like the poster before you said), I don't think it's worth it to try to figure out exactly what's going on (unless you just enjoy it, which I completely understand) because the chances of you receiving two S30V, S90V, 154CM, etc. knives that are exactly the same are pretty slim.

When I said notice the difference I ment in how aggressive they cut or not given they are all sharpened the same. You can hear the difference and feel it, well I can anyway.

Like XHP is more aggressive that ZDP is from what I have seen or S30V is more aggressive than AUS-8.

All please keep in mind that the largest difference here is the tests themselves. Even if the testers were to exchange equipment, attempt to mimic the other's procedure and sharpening, and report environmental conditions for each test - the two test procedures themselves are completely different. If Vassili started cutting on a scale, and Ankerson started cutting thread at regular intervals, their results still don't correspond to the results of each of their original tests.

When during the course of his testing does Vassili reach 20 lbs of force to cut through the rope? When is there contact with wood? I agree that since all of Ankerson's cutting involves wood contact that it does not compromise the results - but what it does is makes the test that much more differentiated from Vassili's. When does Ankerson push cut through thread? When does he stop at a predetermined number of rope cuts? They are doing two completely different things with their knives, the only thing in common is that they are using some type of manila rope. For Vassili, it doesn't matter how much force it takes to cut the rope, while that is the performance measure Ankerson grades on. For Ankerson, it doesn't matter how well the edge push cuts thread, while this force is what Vassili grades from.

They would probably have to combine the tests to possibly make a meaningful comparison. Cut the same size rope under as similar as possible conditions, measuring the push cutting force on the same thread with the same scale at the same intervals, while also tracking the force needed to cut the rope on the same scale as well. Push cutting sharpness up to 200 cuts and total number of cuts up to 20 lbs of force would need to both be recorded. The same sharpening system would need to be used, to the same finish and angle, with the same measured sharpness at the start of each test.

That is if you want to compare the tests. They are fine as they are for looking at independently, but you cannot say one is better than the other, since they are different things. Variability exists in both, and it makes repeatable results difficult for a very high level of precision.

Now, for me an issue has always been just how finely must we differentiate the steels themselves? If you control as best you can all the factors you can think of, and the steels score so closely that a change in the weather reverses the ranking - then does it matter that much at that point? I think that you are then dealing with steels too close to bother with worrying about terminal performance differences. Availability, cost, and other factors outside of edge life then become even more important in deciding. Vassili makes very definite decisions about what steel is superior, but many of them are terribly close in measured force, and they aren't tested/evaluated for other factors. Ankerson chooses not to disclose raw data, so we don't know just how different the steels are. He has also told us that the same alloy can more than double the performance by being used in a different knife (geometry and heat treat) They are doing a lot of work, and providing results to the community-but I don't think the results should be used to criticize others. Nothing is perfect, but there is a lot of effort put forth.

It is very difficult (well, impossible) to precisely evaluate alloying when you are actually evaluating a lot more than that all at the same time.

I think the only way is for more to start doing the testing and see what they come up with. The more data points we have the better I think, but then that's my opinion.

There isn't a perfect way to test, well not one that's affordable anyway for most of us unless someone is rich and has a lot of money and time to spend.

Then they would have to have a bunch of blades made exactly the same of all the different steels at different HRC's. Say 15 of each steel at one hardness so you can see how expensive that would be. Then get a CARTA machine and a bunch of test media and run it in a controlled environment.

We would have to have the steels from different batches too just to be sure, so that would be 15 blades at each HRC per batch.

All the blades would have to be tested lets say 5 times and the data collected.

Then after all the raw data is collected it would have to be entered into a software program to be analysed. As you can see the cost could run into Millions with all that would have to be done and the people needed to do it.

Like I said the Guys in the White Lab Coats etc.

And even then after all of that I am positive there would still be people questioning the results.

Yeah even after Millions of dollars and Thousands of man hours the results would still be questioned....

There is no way to win here on this.

 

[STR]

It is very interesting to see so many people are preoccupied with blade steels and such. I honestly don't get the fascination from testing all these random steels. If I've had a blade made of good old 1095, in my use, outperforming S90V, then for me it would be the better steel. Even if a reputable member like Jim tested it and it "scored" way less than the S90V or even a lower end steel.
You use what works best for you, simple as that. Many knives, with same steels, perform differently at times. People should never disregard factors such as hardness, geometry, and sharpening skills. Which all influence edge holding. Also, if when cutting you start applying sideways strain on the edge, the edge now encounters a different force and will probably exhibit different edge deformation, thus different edge retention results.

I agree here and another example would be this. If we take two deer hunters, one very experienced, the other just starting out and take two identical knives, at the same hardness, at the same or as close to the same grind and edge profile and geometry and sharpened in exactly the same way and give those to them we will see different results in each knife. This is a given. The more experienced hunter will likely be able to skin out and field dress far more deer than the inexperienced hunter will because the inexperienced hunter will likely cut more hair rather than take time to separate it, and he will likely run the edge into bone and maybe even the ground or sand or other such things as he works compared to the more experienced hunter. This would be the case regardless of the knife or blade steel they were given so really when you stop to think of it you cannot really define good or bad so much in the steel as in the user using the steel and how he manages it. You could give the experienced hunter a worse blade for edge keeping and hardness and he would still likley make it work longer than a super steel blade given to the inexperienced user. But that is not what we are talking about here for testing is it? For that matter we could do the same test with two experienced or two inexperienced hunters and get different results but my guess is they'd be closer to each other as we test.

The fact is that we have to try to come up with repeatable tests to do that will get as close to repeating progressive steps the same way to determine what is what and how each knife blade tested works. Sure there are variables but that is also a given anytime you are talking about a knife in the human hand. The testing machines cannot duplicate what is done with the hand. I don't believe we get as good or as honest a result using machines and prefer the testing done by users using the actual knives I may buy and own. My guess is, all the nit picking aside, that Jim's tests show quite well what a knife does or is likely to do in the human hand and that they can give a user a pretty good idea of what to expect if he bought this knife tested.

STR

 

[Bill1170]

This last sentence from STR says it nicely. In the end, what we really want to know is how a knife will perform in our hand. There exists the real possibility that handheld testing is a better determinant of this than machine manipulation of a blade.

 

[Noctis3880]

For crying out loud, all this talk of eliminating random variables is just unnecessarily complicating matters.

Speaking as someone who uses his knives, I can say that I far more appreciate "real-world" testing as opposed to CATRA. That is because I am not a robot! My cuts will never be precisely the same each and every time with precisely the same amount of force, direction, and whatever other "random variables" there might be.

IIRC, CATRA tests(at least by Spyderco) are done with different steels at the same Rc. That's just not going to happen in the real world. Each steel has different limits of hardness, and every maker is going to use a different final hardness on their production knives.

 

[Gator97]

I think hardness is the easiest of many other factors to eliminate.
Human factor however, shouldn't be discounted. If I am interested in purely steel properties that's where CATRA comes in.
On the other hand, none of us can match it in a real word/real use and this is where user testing comes in. It's imprecise, varies, etc, but it's far more likely that one of us matches Ankerson's or whoever else's cutting results than catra machine.

 

[sykes3170]

Ok. I think I have it figured out. No test, no matter what is infallible. This will always be the case. There is no perfect human hand, no perfect machine, it's an imperfect world we live in. I'm just grateful to the people(Jim,Vassili,Phil,Ect.) that take the time(alot of time) and work to post these tests for us to look at and learn. This whole bladeforums experience is about sharing and learning. Im thankful that the more knowledgeable Folks do this for us laymen people. Thanks guys, and keep up the good work it is appreciated! One other thing. It's nice to see different opinions and tests. After all, thats why they are called tests not answers.:thumbup: