I am no steel or sharpening expert. I read what Larrin produces and make good use of the charts. I just know what I like and stick to buying carbide rich steels for knives under 6 inches if at all possible. Carbide rich steels are chosen for a reason, they cut better than the older non carbide steels, not just that they are newer.
As to BESS testers, they ONLY test what is under less than one millimeter of the knife blade and the remainder of the blade is ignored. I think Larrin has a better steel tester that slices cardboard test pieces, and that would be a better tester overall of how a knife edge is going to perform. I just don't know, will a BESS tester show that a high carbide steel cuts better? I do not think that is what it is measuring.
I could be wrong about Larrin's steel testing rig too, don't take my word for it.
What testing rig tests the quality of a cut, employing the length of a knife blade?
What do you mean that a carbide rich steel 'cuts better'? This is rather vague and I don't know if you mean cuts longer, gets sharper, etc.
I think that almost all steels can become very sharp. A BESS tester would prove that, but what a BESS tester cannot do is tell you how many carbides are in the blade and how long it will cut.
Given available test results, especially Larrin's repeatable tests of total cards cut by a machine, I think you would agree higher carbide steels cut longer.
Large carbides - For example Cast 440C has huge carbides formed in its microstructure and as a result cuts like a very finely serrated blade without all the inconvenience of sharpening one.
....
Not meaning to derail the thread, but not sure what you mean by "all the inconvenience of sharpening serrated blades"?
If you want the "aggression" of actual serrations: Imo they are actually even a bit easier and quicker to sharpen than PE (see Vivis thread here viewtopic.php?f=2&t=84544#p1349519)
[Just a quick tip that might help, actual discussions about sharpening SE please in that linked thread, not here].
Top three going by pocket-time (update March 24):
- EDC: Endura thin red line ffg combo edge (VG10); Wayne Goddard PE (4V), Endela SE (VG10)
-Mountains/outdoors: Pac.Salt 1 SE (H1), Salt 2 SE (LC200N), and also Wayne Goddard PE (4V)
I am no steel or sharpening expert. I read what Larrin produces and make good use of the charts. I just know what I like and stick to buying carbide rich steels for knives under 6 inches if at all possible. Carbide rich steels are chosen for a reason, they cut better than the older non carbide steels, not just that they are newer.
As to BESS testers, they ONLY test what is under less than one millimeter of the knife blade and the remainder of the blade is ignored. I think Larrin has a better steel tester that slices cardboard test pieces, and that would be a better tester overall of how a knife edge is going to perform. I just don't know, will a BESS tester show that a high carbide steel cuts better? I do not think that is what it is measuring.
I could be wrong about Larrin's steel testing rig too, don't take my word for it.
What testing rig tests the quality of a cut, employing the length of a knife blade?
What do you mean that a carbide rich steel 'cuts better'? This is rather vague and I don't know if you mean cuts longer, gets sharper, etc.
I think that almost all steels can become very sharp. A BESS tester would prove that, but what a BESS tester cannot do is tell you how many carbides are in the blade and how long it will cut.
Given available test results, especially Larrin's repeatable tests of total cards cut by a machine, I think you would agree higher carbide steels cut longer.
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting. Larrin himself makes no such claims that his tests predict real world results. He simply puts forth the data from his tests, the problem is too many conclusions are being drawn from this data which has not been proven to correlate highly. I cannot understand personally why you'd go to all the trouble of modeling with these tests to not even bother to see if the model translates to reality. Cliff Stamp had directly asked Larrin about this on his forum and Larrin's response was that it was simply assumed that the CATRA correlates to reality. That is not science, that is nonsense to me.
We do not cut like machines and CATRA certainly DOES NOT put any lateral loads on the knives which is a common thing in real world cutting. I will agree that if you generally cut to extreme low levels of sharpness then you may find higher carbide steels preferable. I would generally sharpen much more frequently than your average person therefore I find little benefit to high carbide volumes. Actually I'd argue that makes them far less preferable as you lose too many other qualities by gaining the extra carbides. Why would I want a steel that makes it harder for me to resharpen? Fancy stones, more time, etc.
So what you really mean by 'cut better' means that they will cut longer. This isn't necessarily true either because knives do not just blunt by slow wear and there are other factors that influence blunting. Some steels in fact do behave better or worse as far as taking a high sharpness, any steel can get sharp but it depends on how you define 'sharp'. For many simply cutting printer paper equals sharpness, for me I would not really call that knife sharp in a real sense. It's approaching being truly sharp but if it's not popping hairs or cutting newsprint then it's a very low standard.
I am no steel or sharpening expert. I read what Larrin produces and make good use of the charts. I just know what I like and stick to buying carbide rich steels for knives under 6 inches if at all possible. Carbide rich steels are chosen for a reason, they cut better than the older non carbide steels, not just that they are newer.
As to BESS testers, they ONLY test what is under less than one millimeter of the knife blade and the remainder of the blade is ignored. I think Larrin has a better steel tester that slices cardboard test pieces, and that would be a better tester overall of how a knife edge is going to perform. I just don't know, will a BESS tester show that a high carbide steel cuts better? I do not think that is what it is measuring.
I could be wrong about Larrin's steel testing rig too, don't take my word for it.
What testing rig tests the quality of a cut, employing the length of a knife blade?
What do you mean that a carbide rich steel 'cuts better'? This is rather vague and I don't know if you mean cuts longer, gets sharper, etc.
I think that almost all steels can become very sharp. A BESS tester would prove that, but what a BESS tester cannot do is tell you how many carbides are in the blade and how long it will cut.
Given available test results, especially Larrin's repeatable tests of total cards cut by a machine, I think you would agree higher carbide steels cut longer.
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting. Larrin himself makes no such claims that his tests predict real world results. He simply puts forth the data from his tests, the problem is too many conclusions are being drawn from this data which has not been proven to correlate highly. I cannot understand personally why you'd go to all the trouble of modeling with these tests to not even bother to see if the model translates to reality. Cliff Stamp had directly asked Larrin about this on his forum and Larrin's response was that it was simply assumed that the CATRA correlates to reality. That is not science, that is nonsense to me.
We do not cut like machines and CATRA certainly DOES NOT put any lateral loads on the knives which is a common thing in real world cutting. I will agree that if you generally cut to extreme low levels of sharpness then you may find higher carbide steels preferable. I would generally sharpen much more frequently than your average person therefore I find little benefit to high carbide volumes. Actually I'd argue that makes them far less preferable as you lose too many other qualities by gaining the extra carbides. Why would I want a steel that makes it harder for me to resharpen? Fancy stones, more time, etc.
So what you really mean by 'cut better' means that they will cut longer. This isn't necessarily true either because knives do not just blunt by slow wear and there are other factors that influence blunting. Some steels in fact do behave better or worse as far as taking a high sharpness, any steel can get sharp but it depends on how you define 'sharp'. For many simply cutting printer paper equals sharpness, for me I would not really call that knife sharp in a real sense. It's approaching being truly sharp but if it's not popping hairs or cutting newsprint then it's a very low standard.
Show us, do some testing and let's see what you're seeing.
What do you mean that a carbide rich steel 'cuts better'? This is rather vague and I don't know if you mean cuts longer, gets sharper, etc.
I think that almost all steels can become very sharp. A BESS tester would prove that, but what a BESS tester cannot do is tell you how many carbides are in the blade and how long it will cut.
Given available test results, especially Larrin's repeatable tests of total cards cut by a machine, I think you would agree higher carbide steels cut longer.
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting. Larrin himself makes no such claims that his tests predict real world results. He simply puts forth the data from his tests, the problem is too many conclusions are being drawn from this data which has not been proven to correlate highly. I cannot understand personally why you'd go to all the trouble of modeling with these tests to not even bother to see if the model translates to reality. Cliff Stamp had directly asked Larrin about this on his forum and Larrin's response was that it was simply assumed that the CATRA correlates to reality. That is not science, that is nonsense to me.
We do not cut like machines and CATRA certainly DOES NOT put any lateral loads on the knives which is a common thing in real world cutting. I will agree that if you generally cut to extreme low levels of sharpness then you may find higher carbide steels preferable. I would generally sharpen much more frequently than your average person therefore I find little benefit to high carbide volumes. Actually I'd argue that makes them far less preferable as you lose too many other qualities by gaining the extra carbides. Why would I want a steel that makes it harder for me to resharpen? Fancy stones, more time, etc.
So what you really mean by 'cut better' means that they will cut longer. This isn't necessarily true either because knives do not just blunt by slow wear and there are other factors that influence blunting. Some steels in fact do behave better or worse as far as taking a high sharpness, any steel can get sharp but it depends on how you define 'sharp'. For many simply cutting printer paper equals sharpness, for me I would not really call that knife sharp in a real sense. It's approaching being truly sharp but if it's not popping hairs or cutting newsprint then it's a very low standard.
Show us, do some testing and let's see what you're seeing.
I do not respond well to people telling me what to do and I am not the one making strong claims that high carbide steels are superior. That is still very much up for debate and no amount of CATRA tests will prove them superior without the step of proving the model in reality. I have little interest or time in actually taking on the dogma that is 'high carbide'. I speak to it here and there because my experience shows little need for this type of steel.
It's actually on makers such as yourself to actually prove this CATRA model out that it is tied to reality. This has never been done to my knowledge but I'd happy to be wrong here. I don't expect you to do anything so please don't take this the wrong way as I'm only trying to point out some issues I see here. I'm not trying to go on crusade, just present the counterpoint to the popular narrative that is put forth here. Without this sort of skepticism and doubt, it's easy to just take it on face value.
Now, I'm not saying that there are not benefits to high carbide. Clean and soft materials certainly tend to favor carbide volume but in the real world there's very little clean material that's actually being cut and the blunting tends to be very different. For some people, they may work best but they are by no means the best at everything or there simply wouldn't be 100's of grades of steel. There would just be maybe a few.... 'good', 'better', 'best'.... why would anything else exist?
I think that almost all steels can become very sharp. A BESS tester would prove that, but what a BESS tester cannot do is tell you how many carbides are in the blade and how long it will cut.
Given available test results, especially Larrin's repeatable tests of total cards cut by a machine, I think you would agree higher carbide steels cut longer.
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting. Larrin himself makes no such claims that his tests predict real world results. He simply puts forth the data from his tests, the problem is too many conclusions are being drawn from this data which has not been proven to correlate highly. I cannot understand personally why you'd go to all the trouble of modeling with these tests to not even bother to see if the model translates to reality. Cliff Stamp had directly asked Larrin about this on his forum and Larrin's response was that it was simply assumed that the CATRA correlates to reality. That is not science, that is nonsense to me.
We do not cut like machines and CATRA certainly DOES NOT put any lateral loads on the knives which is a common thing in real world cutting. I will agree that if you generally cut to extreme low levels of sharpness then you may find higher carbide steels preferable. I would generally sharpen much more frequently than your average person therefore I find little benefit to high carbide volumes. Actually I'd argue that makes them far less preferable as you lose too many other qualities by gaining the extra carbides. Why would I want a steel that makes it harder for me to resharpen? Fancy stones, more time, etc.
So what you really mean by 'cut better' means that they will cut longer. This isn't necessarily true either because knives do not just blunt by slow wear and there are other factors that influence blunting. Some steels in fact do behave better or worse as far as taking a high sharpness, any steel can get sharp but it depends on how you define 'sharp'. For many simply cutting printer paper equals sharpness, for me I would not really call that knife sharp in a real sense. It's approaching being truly sharp but if it's not popping hairs or cutting newsprint then it's a very low standard.
Show us, do some testing and let's see what you're seeing.
I do not respond well to people telling me what to do and I am not the one making strong claims that high carbide steels are superior. That is still very much up for debate and no amount of CATRA tests will prove them superior without the step of proving the model in reality. I have little interest or time in actually taking on the dogma that is 'high carbide'. I speak to it here and there because my experience shows little need for this type of steel.
It's actually on makers such as yourself to actually prove this CATRA model out that it is tied to reality. This has never been done to my knowledge but I'd happy to be wrong here. I don't expect you to do anything so please don't take this the wrong way as I'm only trying to point out some issues I see here. I'm not trying to go on crusade, just present the counterpoint to the popular narrative that is put forth here. Without this sort of skepticism and doubt, it's easy to just take it on face value.
Now, I'm not saying that there are not benefits to high carbide. Clean and soft materials certainly tend to favor carbide volume but in the real world there's very little clean material that's actually being cut and the blunting tends to be very different. For some people, they may work best but they are by no means the best at everything or there simply wouldn't be 100's of grades of steel. There would just be maybe a few.... 'good', 'better', 'best'.... why would anything else exist?
Yeah, we're just sharing ideas here, that's one of the purposes of a forum, to share different ideas. You have told us what your thoughts, sounds interesting however, it would be more interesting to see if you could find a way to show us your ideas? Perhaps a simple test that can generate some data?
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting. Larrin himself makes no such claims that his tests predict real world results. He simply puts forth the data from his tests, the problem is too many conclusions are being drawn from this data which has not been proven to correlate highly. I cannot understand personally why you'd go to all the trouble of modeling with these tests to not even bother to see if the model translates to reality. Cliff Stamp had directly asked Larrin about this on his forum and Larrin's response was that it was simply assumed that the CATRA correlates to reality. That is not science, that is nonsense to me.
We do not cut like machines and CATRA certainly DOES NOT put any lateral loads on the knives which is a common thing in real world cutting. I will agree that if you generally cut to extreme low levels of sharpness then you may find higher carbide steels preferable. I would generally sharpen much more frequently than your average person therefore I find little benefit to high carbide volumes. Actually I'd argue that makes them far less preferable as you lose too many other qualities by gaining the extra carbides. Why would I want a steel that makes it harder for me to resharpen? Fancy stones, more time, etc.
So what you really mean by 'cut better' means that they will cut longer. This isn't necessarily true either because knives do not just blunt by slow wear and there are other factors that influence blunting. Some steels in fact do behave better or worse as far as taking a high sharpness, any steel can get sharp but it depends on how you define 'sharp'. For many simply cutting printer paper equals sharpness, for me I would not really call that knife sharp in a real sense. It's approaching being truly sharp but if it's not popping hairs or cutting newsprint then it's a very low standard.
Show us, do some testing and let's see what you're seeing.
I do not respond well to people telling me what to do and I am not the one making strong claims that high carbide steels are superior. That is still very much up for debate and no amount of CATRA tests will prove them superior without the step of proving the model in reality. I have little interest or time in actually taking on the dogma that is 'high carbide'. I speak to it here and there because my experience shows little need for this type of steel.
It's actually on makers such as yourself to actually prove this CATRA model out that it is tied to reality. This has never been done to my knowledge but I'd happy to be wrong here. I don't expect you to do anything so please don't take this the wrong way as I'm only trying to point out some issues I see here. I'm not trying to go on crusade, just present the counterpoint to the popular narrative that is put forth here. Without this sort of skepticism and doubt, it's easy to just take it on face value.
Now, I'm not saying that there are not benefits to high carbide. Clean and soft materials certainly tend to favor carbide volume but in the real world there's very little clean material that's actually being cut and the blunting tends to be very different. For some people, they may work best but they are by no means the best at everything or there simply wouldn't be 100's of grades of steel. There would just be maybe a few.... 'good', 'better', 'best'.... why would anything else exist?
Yeah, we're just sharing ideas here, that's one of the purposes of a forum, to share different ideas. You have told us what your thoughts, sounds interesting however, it would be more interesting to see if you could find a way to show us your ideas? Perhaps a simple test that can generate some data?
I agree, data is good in any form but I don't have the means to devote time to this. I wish I had the time but single/kids family life has got my time maxed out these days, I'm lucky to have a few minutes to pop on here a few times a week to make a post or two. It would appear that life has not been kind to me lately but somehow I manage. Just trying to stay grateful for what I have is pretty difficult lately.
The best I could do is offer that there's a few videos that mostly sum up what I'm trying to say that I could link here by Kyley Harris. Cutting time vs. sharpening time, he argues that Victornix has what may be the best ratio between ease of sharpening to use, if that makes sense. I don't have experience with their stuff much but see what he means from other steels, I generally think this is the most sensible way to look at it compared to just raw numbers of how many cuts can it do before it's extremely dull when a few swipes on a rod would have it very sharp again in seconds.
Traditional.Sharpening wrote:
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting.
Hi Traditional.Sharpening,
I'm somewhat curious since you have already expressed not wanting to do any tests yourself, what you think an actual good testing would be? From some of your previous posts you seem always interested in getting scientific evidence, which often means constraining as many variables as possible, such as a CATRA test, but obviously your concern is that this test doesn't reflect the un-mechanical nature of an actual human user. Real use however naturally becomes more objective because of a person's imprecision, so results will become less precise, although if I'm understanding your argument, would be more useful.
If that's the case, what would be your idea of a test that would compare the edge retention of different steels? A manual rope cutting test maybe? Curious what your thought would be.
Also, I think that how much time spent sharpening vs. staying sharp isn't the whole story that can tell us how well a steel will work for someone, because some people can't afford to re-sharpen for a certain period of time for one reason or another, but they still need a sharp knife for that entire duration of the process regardless of how long it takes to get sharp again when they do get the chance resharpen. A perfect example is processing an animal that you have hunted in the woods, many animals hides are rough on edges, some steels require you to sharpen in the middle of the job, which can be very inconvenient when your knife is cover in blood and fat, but it will not be any trouble to get clean and sharp once you get home. People who cut tons of cardboard all day for a living sometimes have a similar situation.
Now hang on, I don’t think the criticism several posts above is fair. If the criticism was meant to be trollish, I shouldn’t respond. But it’s also possible the post in question represents a gross misunderstanding of the scientific process, in which case, someone needs to respond.
The often-heard and well-worn argument that “scientific tests don’t replicate the real world” is a favorite objection—but it doesn’t slow science down any more than a dog chasing a car. If it did, we’d still be living the lifestyle of the late 1600s or earlier.
Scientists refer to the issue raised as external validity. You could make this objection against most scientific studies, maybe all scientific studies, because a good study attempts to eliminate extraneous variables to more precisely determine cause. However, this allows detractors to claim the extraneous variables, being excluded, invalidate the study because it’s not realistic—because it hasn’t included all possible variables. Claiming lack of external validity is kind of the standard, fall-back objection to any study you don’t like.
Of course, if a study didn’t control for extraneous variables, it would be invalid. That would be the problem of including confounds in the study—which is an even worse problem. So basically you can criticize most any single scientific study on the basis of either internal or external validity. It’s a ‘darned if you do and darned if you don’t’ situation. But it’s harder to criticize an entire field of studies—which is still emerging and developing into what might be called ‘knife steel science.’ But it’s silly to criticize an emerging field for not studying every variable; that comes with time and more researchers in the field.
Science proceeds by establishing a beach-head, and then expanding from there. It doesn’t claim to prove anything (and especially not everything), which is why a good scientist “makes no such claims.” It’s not a weakness, as implied; it is how science proceeds. As a science expands, more variables are examined. In the critique above, the variable of lateral loads is mentioned. That’s a variable that Thomas hasn’t methodically tested (to my knowledge) and yes, it would be nice if someone developed a methodology to test it. Typically, the person who objects to a model because it doesn’t incorporate a particular variable, is the person who takes on the project of testing that variable—provided they have the training to do so. I think testing lateral load is a good idea. I’m looking forward to seeing results. But I see no reason to toss previous research because it didn’t include one particular variable. (I doubt anyone else does either.)
Now we need to address the criticism of “not been proven to actually correlate to real world cutting.” (1) As an aside, it’s laymen who say “prove,” whereas scientists are much more conservative, only saying whether a hypothesis is supported or not. (2) More importantly, “real world cutting” is not defined. What is “real world cutting”? Does it vary from person to person? From medium to medium? From environment to environment? “Real world cutting” would need to be made concrete and precise before it could become a testable variable. CATRA testing is one widely accepted partial measure. Nobody says it’s the only measure or even the best measure, it’s just one measure that happens to be admirably objective and precise and widely acknowledged. (3) Why ask for a correlation? If you’re doing good science you want more than a correlation, which is a low standard. You want a formula. Larrin published a regression formula…a startlingly good one, which obtained an R-squared of .79 with a linear association and .83 with a quadratic! A steel’s response to lateral force could be added as a predictive variable to this (or other) equation and it might refine it further (or it might not—results are a gamble). That’s how science progresses, by adding information to the existing. Not by calling previous work “nonsense.”
I think it’s incumbent for critics of science, or of particular scientists, to have a basic understanding of what science is attempting to do and how it proceeds.
Steel novice who self-identifies as a steel expert. Proud M.N.O.S.D. member 0003. Spydie Steels: 4V, 15V, 20CV, AEB-L, AUS6, Cru-Wear, HAP40, K294, K390, M4, Magnacut, S110V, S30V, S35VN, S45VN, SPY27, SRS13, T15, VG10, XHP, ZWear, ZDP189
Traditional.Sharpening wrote:
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting.
Hi Traditional.Sharpening,
I'm somewhat curious since you have already expressed not wanting to do any tests yourself, what you think an actual good testing would be? From some of your previous posts you seem always interested in getting scientific evidence, which often means constraining as many variables as possible, such as a CATRA test, but obviously your concern is that this test doesn't reflect the un-mechanical nature of an actual human user. Real use however naturally becomes more objective because of a person's imprecision, so results will become less precise, although if I'm understanding your argument, would be more useful.
If that's the case, what would be your idea of a test that would compare the edge retention of different steels? A manual rope cutting test maybe? Curious what your thought would be.
Also, I think that how much time spent sharpening vs. staying sharp isn't the whole story that can tell us how well a steel will work for someone, because some people can't afford to re-sharpen for a certain period of time for one reason or another, but they still need a sharp knife for that entire duration of the process regardless of how long it takes to get sharp again when they do get the chance resharpen. A perfect example is processing an animal that you have hunted in the woods, many animals hides are rough on edges, some steels require you to sharpen in the middle of the job, which can be very inconvenient when your knife is cover in blood and fat, but it will not be any trouble to get clean and sharp once you get home. People who cut tons of cardboard all day for a living sometimes have a similar situation.
Rope cutting is generally soft, clean material. You'd need to cut dirty materials as you find them, dirty rope would work though. Don't buy lumber at the store, go in the woods and cut what you find as it's all dirty.
I'm sorry but I disagree that a simple ceramic rod would be hard to use in the field processing an animal. No more dextrous than cutting the animal apart from how I'd use it anyways. Maybe hard in the dark if you cannot see though.
Now hang on, I don’t think the criticism several posts above is fair. If the criticism was meant to be trollish, I shouldn’t respond. But it’s also possible the post in question represents a gross misunderstanding of the scientific process, in which case, someone needs to respond.
The often-heard and well-worn argument that “scientific tests don’t replicate the real world” is a favorite objection—but it doesn’t slow science down any more than a dog chasing a car. If it did, we’d still be living the lifestyle of the late 1600s or earlier.
Scientists refer to the issue raised as external validity. You could make this objection against most scientific studies, maybe all scientific studies, because a good study attempts to eliminate extraneous variables to more precisely determine cause. However, this allows detractors to claim the extraneous variables, being excluded, invalidate the study because it’s not realistic—because it hasn’t included all possible variables. Claiming lack of external validity is kind of the standard, fall-back objection to any study you don’t like.
Of course, if a study didn’t control for extraneous variables, it would be invalid. That would be the problem of including confounds in the study—which is an even worse problem. So basically you can criticize most any single scientific study on the basis of either internal or external validity. It’s a ‘darned if you do and darned if you don’t’ situation. But it’s harder to criticize an entire field of studies—which is still emerging and developing into what might be called ‘knife steel science.’ But it’s silly to criticize an emerging field for not studying every variable; that comes with time and more researchers in the field.
Science proceeds by establishing a beach-head, and then expanding from there. It doesn’t claim to prove anything (and especially not everything), which is why a good scientist “makes no such claims.” It’s not a weakness, as implied; it is how science proceeds. As a science expands, more variables are examined. In the critique above, the variable of lateral loads is mentioned. That’s a variable that Thomas hasn’t methodically tested (to my knowledge) and yes, it would be nice if someone developed a methodology to test it. Typically, the person who objects to a model because it doesn’t incorporate a particular variable, is the person who takes on the project of testing that variable—provided they have the training to do so. I think testing lateral load is a good idea. I’m looking forward to seeing results. But I see no reason to toss previous research because it didn’t include one particular variable. (I doubt anyone else does either.)
Now we need to address the criticism of “not been proven to actually correlate to real world cutting.” (1) As an aside, it’s laymen who say “prove,” whereas scientists are much more conservative, only saying whether a hypothesis is supported or not. (2) More importantly, “real world cutting” is not defined. What is “real world cutting”? Does it vary from person to person? From medium to medium? From environment to environment? “Real world cutting” would need to be made concrete and precise before it could become a testable variable. CATRA testing is one widely accepted partial measure. Nobody says it’s the only measure or even the best measure, it’s just one measure that happens to be admirably objective and precise and widely acknowledged. (3) Why ask for a correlation? If you’re doing good science you want more than a correlation, which is a low standard. You want a formula. Larrin published a regression formula…a startlingly good one, which obtained an R-squared of .79 with a linear association and .83 with a quadratic! A steel’s response to lateral force could be added as a predictive variable to this (or other) equation and it might refine it further (or it might not—results are a gamble). That’s how science progresses, by adding information to the existing. Not by calling previous work “nonsense.”
I think it’s incumbent for critics of science, or of particular scientists, to have a basic understanding of what science is attempting to do and how it proceeds.
CATRA is widely accepted but it's based on an ASSUMPTION that it models performance in general. It always has from the very beginning been based on an assumption that this is how cutting works but we are NOT robots/machines. The human error will always dominate real world use. The problem is really centered on the fact that the assumption is so strong that many including Larrin go so far as to label CATRA rankings as 'edge retention' as though that were the only factor.
I'm not going to get into it in general but as you can hopefully see the CATRA model has serious issues and hasn't even begun to be tested to see if the model is even remotely tied to reality. I'd generally prefer human generated data, not machine cutting data as we are not machines. Human cutting data is not perfect but if done in large enough volume it helps a lot. I'm not going to continue this discussion further here folks, I've spent my time and energy quota here for the week here.
But it’s also possible the post in question represents a gross misunderstanding of the scientific process, in which case, someone needs to respond.
Bwahahaha! Lookit Mister Bolster, gonna singlehandedly take on the Tik-Tok Science Followers!
Sorry, man. I'm laughing WITH you.
I've stopped discussing science with almost everyone. I found that most people's eyes just glaze over. Others become hostile because they follow Twitter influencers who tell them that science is a sham.
Party on, Garth.
Enjoy the rest of your holiday weekend.
I thought Shawn’s testing was excellent and welcome tests by others, as well. Empirical evidence is valuable, and can help to support or disprove theoretical models.
I am no steel or sharpening expert. I read what Larrin produces and make good use of the charts. I just know what I like and stick to buying carbide rich steels for knives under 6 inches if at all possible. Carbide rich steels are chosen for a reason, they cut better than the older non carbide steels, not just that they are newer.
As to BESS testers, they ONLY test what is under less than one millimeter of the knife blade and the remainder of the blade is ignored. I think Larrin has a better steel tester that slices cardboard test pieces, and that would be a better tester overall of how a knife edge is going to perform. I just don't know, will a BESS tester show that a high carbide steel cuts better? I do not think that is what it is measuring.
I could be wrong about Larrin's steel testing rig too, don't take my word for it.
What testing rig tests the quality of a cut, employing the length of a knife blade?
What do you mean that a carbide rich steel 'cuts better'? This is rather vague and I don't know if you mean cuts longer, gets sharper, etc.
I think that almost all steels can become very sharp. A BESS tester would prove that, but what a BESS tester cannot do is tell you how many carbides are in the blade and how long it will cut.
Given available test results, especially Larrin's repeatable tests of total cards cut by a machine, I think you would agree higher carbide steels cut longer.
I do not agree as Larrin's model has not been proven to actually correlate to real world cutting. Larrin himself makes no such claims that his tests predict real world results. He simply puts forth the data from his tests, the problem is too many conclusions are being drawn from this data which has not been proven to correlate highly. I cannot understand personally why you'd go to all the trouble of modeling with these tests to not even bother to see if the model translates to reality. Cliff Stamp had directly asked Larrin about this on his forum and Larrin's response was that it was simply assumed that the CATRA correlates to reality. That is not science, that is nonsense to me.
We do not cut like machines and CATRA certainly DOES NOT put any lateral loads on the knives which is a common thing in real world cutting. I will agree that if you generally cut to extreme low levels of sharpness then you may find higher carbide steels preferable. I would generally sharpen much more frequently than your average person therefore I find little benefit to high carbide volumes. Actually I'd argue that makes them far less preferable as you lose too many other qualities by gaining the extra carbides. Why would I want a steel that makes it harder for me to resharpen? Fancy stones, more time, etc.
So what you really mean by 'cut better' means that they will cut longer. This isn't necessarily true either because knives do not just blunt by slow wear and there are other factors that influence blunting. Some steels in fact do behave better or worse as far as taking a high sharpness, any steel can get sharp but it depends on how you define 'sharp'. For many simply cutting printer paper equals sharpness, for me I would not really call that knife sharp in a real sense. It's approaching being truly sharp but if it's not popping hairs or cutting newsprint then it's a very low standard.
I don't think I ever said that CATRA tests modeled real world numbers, but they do. The results may be a multiplier, such as *1.5 to get the actual numbers, and they are repeatable, so they are very scientific.
You do not agree that Larrin's model has been proven to actually correlate to real world cutting, but there is a guy who has been doing real world cutting tests on sisal on YouTube for years and they match up with Larrin's CATRA results. I forget the guys name, but his account is "CEDRIC & ADA GEAR AND OUTDOORS" and his tests results are available for FREE.
Im probably one of least finicky people about steel here. Any good steel is generally good enough for me. I get the passion behind the science of steel but as a regular knife user first and foremost, design comes way ahead of the steel for me…
Seems like the general crowd of regular knife users nowadays are way down the scientific rabbit hole of steel relativity, not quite sure if it’s necessary, or maybe its just me.
Current “dream collection” of knives
temperance 1, lil temperance 1 serrated leaf, black micarta calypso jr & calypso, cocobolo kopa, stainless serrated harpy, stainless cricket
Ive personally done probably close to 150 cut testing trials of my free will. Obviously mine were more loosely controlled than Doctor Larrins. But often times my numbers would match his catra results sometimes not. Mine were spyderco production folders/mules whereas there were specific heat treatments Shawn did for the catra testing. There will always be differences within bulk batches/ manufacturers etc. In fact my 15V results were averaged with 2 knives bcuz i saw noticeable differences in testing between the 2. My toughness testing results differ from what the good doctor put up for 15V however Shawns heat treat increased the toughness higher than the coupon. Under controlled testing, lateral stresses are for the most part not used. In my view that is a biproduct of user error not the steel itself. Whether its using a knife beyond functional sharpness or not matching the edge angle in cutting. Catra coupons all supported the same blade geometry, my testing ruled out blade geometry and focused on just the cutting apex itself. I dont think cutting thick rubber or dense plastic is sustainable for long term testing, and its more of a testament to overall ergonomics. Bcuz I could not put a direct value to lateral stresses, I chose a different route. I chose to use an ice block to see how well a knife can handle impacts on the ice in combination with my standard sanding rolls. I usually run my edges around 13 dps on most steels except a few. Ive done mostly 1k edges for testing, but a few 400 ones to see if certain steels performed better or not. I did a few 44 grit edges but didnt like how those tested and moved on. When the steel performed poorly in those tests, I knew to increase the edge angle. If it did well I kept the edge angle and moved on. I had to take a break from testing due to my wife being run over by a drunk driver. What i was aiming for was to have a edge stability ranking system once i completed around 30 different samples. Perhaps im too jaded by my own testing, but i feel this indirect path would bear fruit at some point. I for one appreciate the effort Larrin and Shawn put into these tests.
"Nothing is built on stone; all is built on sand, but we must build as if the sand were stone."
Now hang on, I don’t think the criticism several posts above is fair. If the criticism was meant to be trollish, I shouldn’t respond. But it’s also possible the post in question represents a gross misunderstanding of the scientific process, in which case, someone needs to respond.
The often-heard and well-worn argument that “scientific tests don’t replicate the real world” is a favorite objection—but it doesn’t slow science down any more than a dog chasing a car. If it did, we’d still be living the lifestyle of the late 1600s or earlier.
Scientists refer to the issue raised as external validity. You could make this objection against most scientific studies, maybe all scientific studies, because a good study attempts to eliminate extraneous variables to more precisely determine cause. However, this allows detractors to claim the extraneous variables, being excluded, invalidate the study because it’s not realistic—because it hasn’t included all possible variables. Claiming lack of external validity is kind of the standard, fall-back objection to any study you don’t like.
Of course, if a study didn’t control for extraneous variables, it would be invalid. That would be the problem of including confounds in the study—which is an even worse problem. So basically you can criticize most any single scientific study on the basis of either internal or external validity. It’s a ‘darned if you do and darned if you don’t’ situation. But it’s harder to criticize an entire field of studies—which is still emerging and developing into what might be called ‘knife steel science.’ But it’s silly to criticize an emerging field for not studying every variable; that comes with time and more researchers in the field.
Science proceeds by establishing a beach-head, and then expanding from there. It doesn’t claim to prove anything (and especially not everything), which is why a good scientist “makes no such claims.” It’s not a weakness, as implied; it is how science proceeds. As a science expands, more variables are examined. In the critique above, the variable of lateral loads is mentioned. That’s a variable that Thomas hasn’t methodically tested (to my knowledge) and yes, it would be nice if someone developed a methodology to test it. Typically, the person who objects to a model because it doesn’t incorporate a particular variable, is the person who takes on the project of testing that variable—provided they have the training to do so. I think testing lateral load is a good idea. I’m looking forward to seeing results. But I see no reason to toss previous research because it didn’t include one particular variable. (I doubt anyone else does either.)
Now we need to address the criticism of “not been proven to actually correlate to real world cutting.” (1) As an aside, it’s laymen who say “prove,” whereas scientists are much more conservative, only saying whether a hypothesis is supported or not. (2) More importantly, “real world cutting” is not defined. What is “real world cutting”? Does it vary from person to person? From medium to medium? From environment to environment? “Real world cutting” would need to be made concrete and precise before it could become a testable variable. CATRA testing is one widely accepted partial measure. Nobody says it’s the only measure or even the best measure, it’s just one measure that happens to be admirably objective and precise and widely acknowledged. (3) Why ask for a correlation? If you’re doing good science you want more than a correlation, which is a low standard. You want a formula. Larrin published a regression formula…a startlingly good one, which obtained an R-squared of .79 with a linear association and .83 with a quadratic! A steel’s response to lateral force could be added as a predictive variable to this (or other) equation and it might refine it further (or it might not—results are a gamble). That’s how science progresses, by adding information to the existing. Not by calling previous work “nonsense.”
I think it’s incumbent for critics of science, or of particular scientists, to have a basic understanding of what science is attempting to do and how it proceeds.
CATRA is widely accepted but it's based on an ASSUMPTION that it models performance in general. It always has from the very beginning been based on an assumption that this is how cutting works but we are NOT robots/machines. The human error will always dominate real world use. The problem is really centered on the fact that the assumption is so strong that many including Larrin go so far as to label CATRA rankings as 'edge retention' as though that were the only factor.
I'm not going to get into it in general but as you can hopefully see the CATRA model has serious issues and hasn't even begun to be tested to see if the model is even remotely tied to reality. I'd generally prefer human generated data, not machine cutting data as we are not machines. Human cutting data is not perfect but if done in large enough volume it helps a lot. I'm not going to continue this discussion further here folks, I've spent my time and energy quota here for the week here.
Nice breakdown Bolster, well argued and respectfully presented.
What I gather from Traditional.Sharpening at this point is that he wants knives tested for his specific use case but not tested by himself? Anyway, it is clear that his opinions tend to stem from his personal preference for steel, and as far as preference goes, that will depend entirely on each persons taste.
Testing from Larrin and that of BBB here help give us data that we can use to try to predict how a steel will behave under certain circumstances, but will not always reflect each person's use case, which is in the end entirely impossible. However, we can use such data to help us determine if a steel is likely to suit our preferences. As always, the data can only give us so much, but that's a given. However, without data as a baseline we would often be shooting in the dark.
As far as user testing goes though, I don't know that I have ever seen anyone suggest based on their use that, for example, 1095 holds an edge longer than s30v, or s30v longer than Rex45. In general, user testing seems to reflect Larrin's numbers without absurd deviation. Even with kitchen knives, which I don't think need high wear resistance to hold an edge well, I can't say from what I have seen that 80crv2 will hold an edge longer than Hap40.
So to sum it up, Larrin and BBB's testing is both useful and does have evidence to support it reflecting real use, and each persons preference in steel will be different depending on what they want in a steel, as well as by your use case, but use case is specific to you and no one can test a knife for your particular situation for you.
What would the similarity be, between lateral load (however measured) and toughness? Would we not expect high toughness steels to handle a higher lateral load? The various tests of toughness are well-developed already, so a case would need to be made that 'handing lateral load' is something substantially different than toughness.
For the record,Thomas addressed CATRA vs "Real Life" in his post "Can CATRA predict Rope Cutting Performance?":
"The third article also pointed out many potential deficiencies in the CATRA test, such as the fact that in “real” cutting there is likely more stress on the edge, especially lateral forces...Another point brought up by critics of the CATRA test is that the silica-impregnated cardstock is not representative of real materials that might be cut with a knife. Based on these kinds of questions I wanted to find out if the CATRA test is actually a useful prediction of slicing edge retention, or if it is just a controlled, scientific test that measures one specific thing but has little applicability when it comes to predicting knife performance, even when limited to slicing edge retention."
Thomas found R-squared* of .84 (after controlling for edge thickness) for Ankerson tests; of .66 for Cedric and Ada (which did not give edge thickness, so it couldn't be controlled, thus reducing the R-squared value); and .65 for Sandor data when one outlier was removed. Those are all high R-squared numbers in my book. Thomas concluded:
"...even with these limitations CATRA results look very similar to rope cutting by people. Therefore, CATRA looks to be a good test for slicing edge retention."
But it's science--virtually every dependent variable can be improved or at least supplemented. What would be the improved or supplemented or evolved version of an edge test?
(* Don't confuse R-squared with correlation, folks! R-squared is a higher hurdle; if you want to think of R-squared in correlation terms, although they are technically measuring different things, un-square it by taking the square root.)
Steel novice who self-identifies as a steel expert. Proud M.N.O.S.D. member 0003. Spydie Steels: 4V, 15V, 20CV, AEB-L, AUS6, Cru-Wear, HAP40, K294, K390, M4, Magnacut, S110V, S30V, S35VN, S45VN, SPY27, SRS13, T15, VG10, XHP, ZWear, ZDP189
