A medium bounds for performance : chopping

[Jerry Hossom]

How hard is it to quantify the skill needed to put the edge of a blade on a nail which is laying flat on a piece of wood and hit the spine of the blade with a hammer hard enough to sever the nail? It really doesn't take a lot of practice. I've not suggested this be a definitive or universal test of steel quality but it will certainly give someone wanting to know how one blade in one steel and/or edge geometry will stack up against another blade with another steel and/or edge geometry. Since it's not a very rigorous test according to Cliff, I'm surprised more people don't try it for themselves. They have nothing to lose since there's so little risk of harming the blade... according to Cliff. Of course, if the blade does fall apart that would make the test more universal and we'd love to hear about it.

Does the individual skill used to chop some number of logs of spruce enter into validating that as a test of steel performance?

In all these discussions of how sharp something is after how much use after having been sharpened by some means to some geometry, how are we to judge the accuracy of the data and/or the veracity of the person reporting the results? We do seem to be listening to advice that suggests the cheapest of steels can chop wood as long as anyone would care to without significant dulling, a thought that tends to run afoul of most experience and virtually all common sense.

I think sensibly you can forget about edge retention via wear for chopping tools, it is simply too slow for even rather low end steels as illustrated here

Wow Cliff, that's quite a statement, especially since the edge you're talking about still shaves which makes it an edge most people would be happy with. You'd crucify any knifemaker who had the temerity to say such a thing about high end steels. I'm not even sure many people would believe him if he posted such a thing here. And I agree, the person selling a product should never be the person who tests the product. That's understood. It's sort of like the person spreading the bull$hit should never be the person who creates it, right?

 

[hardheart]

Wow Cliff, that's quite a statement, especially since the edge you're talking about still shaves which makes it an edge most people would be happy with. You'd crucify any knifemaker who had the temerity to say such a thing about high end steels. I'm not even sure many people would believe him if he posted such a thing here.

Do you mean he'd crucify a maker who claimed the knife of steel designation X would still shave after chopping because he'd say it wouldn't be possible; or he'd crucify the maker for saying as much because, as he claims in this thread, maintaining a shaving sharp edge after hundreds of chops into wood is something crappy steel can do, and therefore is no measure of high end steel?

 

[Cliff Stamp]

... but it will certainly give someone wanting to know how one blade in one steel and/or edge geometry will stack up against another blade with another steel and/or edge geometry. Since it's not a very rigorous test according to Cliff ...

Never said that, it is in fact impossible to say that in general without knowing what the test is supposed to measure because without this you can not say if it is accurate or not, that is basic. What I actually said was that static nail cutting was not representative of dynamic impacts in use. It is however a very rigorous way to test the ability of a knife to cut nails in half.

Assuming the cuts are decently controlled then it is basically a test of the compression strength of the edge which will never be faulted by a nail because it is too soft. Only if the user skill is not high enough and the nail turns then the edge will be laterally loaded and can deform or chip. Thus the extent of edge damage is highly dependent on user skill of that particular chop so that is essentially what you are measuring.

Now if you chopped a thousand nails and averaged the results this would smooth out the deviations from one chop to another and remove that variable. You would also want the chopper to have no incentive to favor one steel over the other and ideally not tell them which one is which. And assuming you did all of this you could then argue that you have proven which person+knife makes a better static nail chopper.

Now if you want to measure the yield point, then simply have a few small strips hardened, very thin, and load them with weights (or a simple scale) and measure the yield point. This would be far cheaper than making a knife and give far more accurate and precise values than trying to infer this from the above nail chopping. You could also just ask the steel manufacturers for the yield data.

Does the individual skill used to chop some number of logs of spruce enter into validating that as a test of steel performance?

The skill influences the results significantly yes, as for invalidating them, that would depend on what you tried to conclude. As always you have to see if the conclusion reached is valid based on the data or methods. This is basic experimental science. As I noted there are methods you can use to deal with the problems of such comparison and yes I use them.

...especially since the edge you're talking about still shaves which makes it an edge most people would be happy with.

That is the point. Since this relatively low end axe, with a ~53 HRC edge does that easily, then it would seem rather pointless to demand high wear resistance is necessary when even this low wear steel does not wear significantly cutting well seasoned woods.

-Cliff

 

[Jerry Hossom]

Then, with reasonable care there should be no harm to the edge. I invite our readers to try it.

I agree, damage should be minimal, but the nature and extent of the damage can be enlightening. Try it, folks.

 

[hardheart]

yes, with reasonable care, not like how I did it, breaking a couple knives in the process.

I would suggest starting with planning time in excess of the period it takes to track down the box of nails in the shed. And remember, an off target blow when driving a nails means a bent nail. An off target blow when cutting a nail with a small knife means a broken knife.

In a way, I think it just shows the obvious, we have both knives and cold chisels for a reason (yep, I'm going to polish up the edge of a cold chisel now to see what I get...)

 

[Jerry Hossom]

So you're suggesting it really is a pretty rigorous challenge?

You and Cliff better talk this over.

 

[hardheart]

I dunno, the knives did ok when I hit straight, minor chipping/denting. But I took out some serious chunks when my grip was off. Anyone planning on doing the same, watch your eyes & fingers if your nickname is lightning (never strikes the same spot twice )

 

[thombrogan]

This is a 3.5" concrete nail, 12 hits with a 26 oz framing hammer to cut directly through. No damage to the edge of the hatchet. While there are makers who advocate this test, Hossom for one, this is more of a sideshow event because as long as you do it carefully it is no problem for any knife. I have done it with A. G. Russell Deerhunters (0.010"/10 degrees) so it is a joke for anything with a significant edge profile.

Cliff, that looks a bit out of line.

You and Jerry may argue over the validity of that test and its corelation with real-life uses, but I suspect Jerry uses the test because he believes it gives him needed feedback. Where steels such as CPM-1V don't pass that test using Hossom's edges, it would appear that it's valid for the knives Jerry makes. Is it a potential selling point? Well, yes. If Hossom believes the test is important and his knives pass that test, why not tell the world? It'd be counterproductive not to.

I have no doubt in Hossom's sincerity with his performance of that test and think that your window of oppurtunity to inform him of your belief that it mostly tests motor-skills was lost when you labeled the test "a sideshow event."

 

[Jerry Hossom]

"minor chipping/denting" is what you're looking for. Which it is and how "minor" can tell you quite a bit about a steel's failure potential. It was indeed what turned me off with CPM-1V.

The more your edge is off square with the nail, the greater the lateral force applied when you hit it. The result can mean bigger chips. And for sure you don't want to strike twice in the same place. The first chip is a stress riser, a second hard hit in the same spot will turn the chip into a crack, or worse.

That btw, is worth remembering when you create "toothy" edges. Those little notches are tiny little stress risers.

 

[Cliff Stamp]

Where steels such as CPM-1V don't pass that test using Hossom's edges, it would appear that it's valid for the knives Jerry makes.

It is very valid to test the ability of a knife to chop nails, beyond that it is too subject to variation to draw conclusions as hardheart showed dramatically. As for the conclusions drawn, that test has lead Hosson to reach a severely flawed conclusion which is that a high carbide fraction is needed to keep the edge from deforming and that steels like 12C27M are prone to ease of edge rolling. I proposed a simple counter example, take a steel fully annealed with a high carbide volume now chop up some nails. Only as the blade is hardened (key word) it becomes resistant to deformation.

Some actual materials facts; the yield strength of L6, which is the point at which the steel deforms under force and it permanently deformed, is 30% higher than the yield point of A2 with both at 58 HRC. The much lower carbon and lower carbide L6 is actually much stronger than the higher carbon and high carbide A2. Note how when Alvin hardened a bunch of L6 strips he found them very difficult to break, that is why. The carbides and higher carbon content of A2 do not make it stronger, they make it weaker. The really high carbide steels like D2 are so brittle that you will not even find tensile data on them.

In regards to conclusions in general from impact damage, a big concern is variability. When I chopped the Fiskars into the nail which was in the wood, out of twelve impacts, only three caused the edge to visibly deform and in each case the damage was significantly different. Thus only a 25% chance (based on that sample) that damage would be caused on a chop and in each case the depth and extent was not identical. Now make a few comparisons like that and see if they are representative.

So you're suggesting it really is a pretty rigorous challenge?

He noted it is strongly technique dependent and that getting perfect chops is an issue, he provided his own data on this awhile back noting how the damage was highly variable and not well correlated to the steel but more to user variability.

-Cliff

 

[Jerry Hossom]

proposed a simple counter example, take a steel fully annealed with a high carbide volume now chop up some nails. Only as the blade is hardened (key word) it becomes resistant to deformation.

Whoever said otherwise. Sorry, but that has no relevance whatever to what I was saying. All of these discussions assume the carbides are in a martensite matrix.

The carbides and higher carbon content of A2 do not make it stronger, they make it weaker. The really high carbide steels like D2 are so brittle that you will not even find tensile data on them.

Again, I think you're confusing toughness and strength, as well as hardness and strength. With CPM-1V at Rc59, the steel in thin sections is readily deformed by hard impacts. I found that to be the case with nail tests and Rob Simonich had similar experiences with whatever he was chopping with it. It was disappointing, because we both felt the steel should be ideal for choppers. Maybe it is for hatchets and swords which have robust edges, but not for knives that need to cut as well as chop. Indeed, if you look at its composition as well as toughness and wear data it should fullfill every low alloy advocate's idea of a perfect steel. http://www.crucibleservice.com/datash/ds1Vv5.pdf?CFID=1469513&CFTOKEN=70410921 And if all a knifemaker wanted was "hype", it has super hype potential. I'm pretty sure it could kick S5 and S7 booty, but I don't think it makes a very good knife steel and told Crucible that shortly after it came out. In fact, they first rolled the steel to knife thicknesses at my request, so they knew what was planned and really didn't take exception to my findings. I don't think they've ever advertised it for use in knives as a result of those "nail" tests. Then again, with all of this low alloy hype going on, maybe we should revisit the steel, play with the heat treat a little, and see what we can make of it.

In regards to conclusions in general from impact damage, a big concern is variability. When I chopped the Fiskars into the nail which was in the wood, out of twelve impacts, only three caused the edge to visibly deform and in each case the damage was significantly different. Thus only a 25% chance (based on that sample) that damage would be caused on a chop and in each case the depth and extent was not identical. Now make a few comparisons like that and see if they are representative.

Describe what you mean by "in the wood". I'm not sure I know the condition you're trying to describe. Clearly your test is more variable than mine because the nail lying flat on a board is a pretty easy target to hit with some accuracy each time. Does it take reasonable care to hit it precisely? I didn't think so, and the damage has always been fairly consistent each time I've done it. I am definitely not adept at using a hammer, but I do try not to flinch which I suppose could throw off your aim. In truth though, I had not anticipated anyone hitting the same spot twice nor hitting so wildly as to cause the blade to deflect meaningfully off perpendicular, causing heavy side loading.

8d Common Bright Nails from Home Depot are available to everyone in North America. They are made of mild steel (1016 I believe) with no coatings or finished and are remarkably consistent. Length is irrelevant. I hammer the side of the head into the board so the shank lies flat and stays in place until the cut.

He noted it is strongly technique dependent and that getting perfect chops is an issue, he provided his own data on this awhile back noting how the damage was highly variable and not well correlated to the steel but more to user variability.

I guess some users are more variable than others. Again, I would invite people to try the test, preferably starting with a knife they don't particularly cherish and see how it fails. Some steels chip, some deform, and some are more highly dependent the edge geometry used.

Remember though, because you have knife in 440C which might chip doesn't mean that all knives in 440C will chip or that 440C is a failed steel. Some will be heat treated better than others and some edges will be shaped to better tolerate the shock than others. And some knives were just never intended to experience shock, using thin steel and very fine edges. I've not tested an Opinel this way, but I wouldn't expect a happy ending. The subject here was a Chopper IIRC. That was also the topic in another, similar thread that also got lost in metallurgical symantics.

Comparisons require some thought to the tasks intended, the steel types preferred (stainless, etc.), the appropriate hardness of each steel for each type of blade, the edge geometry appropriate to the tasks intended and the steel used, and the final finish on the edge. Knifemakers are at some advantage here, because we can make AND modify what we want to test to see how what we will eventually make with a steel will perform, so we accummulate some useful knowledge in these areas. But as everyone was admonished earlier, you shouldn't listen to the person who is selling the knife, even if he isn't actually trying to sell it.

 

[Cliff Stamp]

All of these discussions assume the carbides are in a martensite matrix.

Ok, temper the martensite to a low hardness and then repeat the cutting, same principle applies. The carbides actually grow in size when the temper is drawn yet the resistance to deformation decreases.

Again, I think you're confusing toughness and strength, as well as hardness and strength.

The values I quoted were strength, the resistance to deformation. L6 is also much tougher than A2 in regards to impact.

Describe what you mean by "in the wood".

I posted a picture, drive the nail into the wood and just chop the wood as normal to try and clear out a chip.

-Cliff

 

[Jerry Hossom]

The carbides actually grow in size when the temper is drawn yet the resistance to deformation decreases.

Carbide content remains the same, but resistance to deformation decreases due to reduced hardness of the matrix when you draw the temper. M60S achieved a hardness of Rc60, as will CPM-1V and some of the steels you're promoting. In that respect they resist deformation, of which hardness is a measure. They can still have a low yield strength regardless of hardness, especially in thin sections. In fact it was the photo of the result of another nail test that caused the producers of M60S to reconsider its usefulness in knives.

Cliff, I may be even harder on new high tech steels than you are. While I'm a bit quieter about it, my findings have been respected by at least two steel companies. I think that's somewhat inconsistent with someone who is trying to sell "hype" or whose testing methods are inconclusive, don't you think? AND BTW, I do not receive nor have I ever received any compensation, either monetary or product, for performing these tests. I have received samples from time to time, but none of those have ever gone into a knife I've sold. In fact, I paid several hundred dollars for my 32 x 48" sheet of CPM-1V, none of which has ever been sold.

Consider this. Published steel performance data is not always (seldom is) relevant to what we create with them. Steel companies simply don't test steel in thin sections for attributes we consider important to knife edges. When you see a Charpy C-notch test result it has been performed on a bar of steel that is 1CM square. There is little about that kind of section that applies to a knife edge at one micron. Subtleties like crack formation and crack propagation, microchipping, plastic deformation, etc are MUCH more important in the world we think important.

Looking at steel company data can be a highly misleading source of information for determining how a steel will perform in a knife, and making judgments based on carbon content alone is hazardous at best.

 

[Cliff Stamp]

Carbide content remains the same

The carbides grow when the temper is drawn as the carbon comes out of the matrix and aggregates on existing carbides, this is what causes the matrix to soften.

They can still have a low yield strength regardless of hardness, especially in thin sections.

In the above I quoted the yield strength of a low carbide vs high carbide steel, the materials properties are the opposite of what you describe.

There is little about that kind of section that applies to a knife edge at one micron.

This is a bit too drastic, do you have any actual data which shows that the data is not correlated and that it is actually a micro-level cause? Quite frankly it seems obvious to me that it is not because the impacts occur on scales a thousand times larger in any kind of chopping use, just consider the size of a nail.

Looking at steel company data can be a highly misleading source of information for determining how a steel will perform in a knife, and making judgments based on carbon content alone is hazardous at best.

Except of course when it says what you want to promote such as the transverse toughness of Crucible steels which said that S30V was several times tougher than 154CM which every maker jumped on, including you, and used it to promote the steel extensively. Did they test this on the very thin sections level that you argue is necessary or do you have a different standard for when materials data supports what you are saying vs when it opposes it?

-Cliff

 

[Broos]

Once again the argument enters into territory far afield from the issue that started it. I wonder why...

Get a knife really sharp (and I'm using the definition of sharp that is commonly understood and defined better than any other) at a 30 degree total (or less) edge. Better yet use one of those very thin edges that cliff often recommends. Cut through a nail with this edge. I don't care how you cut through it. Then post a picture of the edge. I'll be very interested to see one of these edges that has no damage after this. I'll bet it will be very clear where the nail was cut. If you chop a lot, this test would give you some indication of the damage you will get without the risk of a dynamic chop into a nail, which will put the knife at more risk of catastrophic failure. Or you could use this test as a general measure of edge strength & how resistant to abuse your edge will be.

I'm having a little difficulty in figuring out where cliff is coming from here. He afforded Noss the same excuse he gives himself in his testing, that "this is a hobby", "could be improved", "there is some information being obtained and that is a good thing", as well as:

2) Many tests are not actually directly task related, such as charpy (hit a knife with a big hammer), wear (grind a knife against a piece of steel) or corrosion (stick a knife in a salt spray for an hour). They are done to infer properties on tasks which load similar attributes.

The guy is having fun and providing some information to the public. If you feel it could be done better then offer some suggestions keeping in mind :

1) He isn't working for you so demands are kind of idiotic.

Contrast the above with calling Jerry's method of cutting through a nail a "side show". Or his objections against the FFD2 tests. It is obvious his standards for testing vary greatly depending on ?

While it may not be a rigorous scientific test, cutting through a nail does show something definitively - it shows what kind of edge damage you can get cutting through a nail however you did it.

---

And I'll add his descriptions for the material properties tests above are incorrect. A charpy test has nothing to do with hitting a knife with a hammer. It involves hitting a standardized test piece with a known energy, by a MACHINE, and measuring the energy absorbed by the notched test piece. It is difficult to get consistent results with this test unless great care is done making and preparing the test specimen, and the results are not universally accepted by engineers and scientists (at least when I was in school that was the case - we were told the only measure we could expect to achieve was transition temperature of the steel). What the test can often show is where your test piece had a flaw in it. Hitting a knife similarly could be more indicative of geometry, flaws in the steel, or stress risers inherent in the design than it would be of the steel's toughness.

 

[Jerry Hossom]

In the above I quoted the yield strength of a low carbide vs high carbide steel, the materials properties are the opposite of what you describe.

You lost me. What did I describe that this is the opposite of? That a steel can be hard and still have a low yield strength? You doubt that a hardened steel can experience plastic deformation unrelated to its measured hardness? I've shown a photograph of it in the M60S example.

This is a bit too drastic, do you have any actual data which shows that the data is not correlated and that it is actually a micro-level cause? Quite frankly it seems obvious to me that it is not because the impacts occur on scales a thousand times larger in any kind of chopping use, just consider the size of a nail.

You have data to prove it does correlate? Impacts do not occur on scales thousands of times larger. They occur on a very tiny scale all along the edge which is involved in the impact. Cracks begin at the edge, microchipping occurs at the edge, deformation is most prevelant at the edge. Everything about how a steel performs in a knife is the result of things happening or beginning to happen on a very small scale, right at the edge. That's what your whole story of edge stability is all about. The problem with how that story is told is that you tend to ignore failures other than brittle/carbide-displacement failures. You need to also look at the matrix inclusive of carbides and measure how that performs in thin sections under load.

Except of course when it says what you want to promote such as the transverse toughness of Crucible steels which said that S30V was several times tougher than 154CM which every maker jumped on, including you, and used it to promote the steel extensively. Did they test this on the very thin sections level that you argue is necessary or do you have a different standard for when materials data supports what you are saying vs when it opposes it?

I really don't know what "they" tested and I don't recall having seen "their" data prior to my and some other knifemakers doing our own testing and drawing our own conclusions from what we saw with S30V. If you recall, Crucible's original data made a very poor case for using the steel and was if anything counter-productive in supporting the steel's toughness claims. I did in fact study Crucible's data with respect to CPM-1V and it was decisively misleading in determining its usefulness as a knife steel. Crucible, nor any other steel company I'm aware of, routinely perform tests to determine how a steel will behave in geometries like a knife blade/edge. That's one of the reasons Crucible, unlike other steel companies, has established a dialog with knifemakers and knife companies so they can learn from our feedback.

I do have different standards when steel company data supports my own findings as opposed to when it disagrees with my findings. Is that surprising? If their data disagrees with what I find to be true, they are wrong. I've already cited two examples, M60S and CPM-1V, where precisely that happened. In the example of S30V, I supported and continue to support the steel regardless of what their data says.

Cliff, you keep wanting to hang guilt of commercial conflict on me. It won't work. My integrity is much more important than all the money I will ever make on knives. At the same time you ask us to accept that accademia is implicitly honest, when the world is filled with examples of scientific misconduct and misrepresentation. Nor does academia possess a monopoly on intellect. Lots of very smart people have real jobs. I'll even bet there are people reading this who are smarter than both of us, and they must be having a lot of fun at our expense...

 

[Cliff Stamp]

You lost me. What did I describe that this is the opposite of?

L6 is a low carbon and low carbide steel, similar to 12C27M which you much criticised, yet the same L6 is much stronger (and still tougher) than A2 a much higher carbon and carbide volume steel. You do not see the contradiction here between this materials data and your comments about carbide volume and strength?

You have data to prove it does correlate?

Yes, everyone does, anyone that has used large blades anyway. It is straightforward to note that the impact toughness of the shock and similar steels correlated very well to their ability to resist cracking in blade use. Harley for example recently notes this with bainite vs martensite L6. Now which one do you think the standard impact tests will favor strongly.

They occur on a very tiny scale all along the edge which is involved in the impact.

The impact will take place on the scale of the surface contact which in knife contacts for gross impacts is on the order of mm not micrometer.

Cracks begin at the edge, microchipping occurs at the edge, deformation is most prevelant at the edge.

Actually no, your own photographs likely show that because you have deformation of the edge bevel as a whole while the very edge (micron level) is still aligned. Anyone who has chopped knotty wood will have seen at one point the bevel as a whole deformed/turned to the side while the edge is still crisp and sharp. Of course the actual deformation will occur on slip planes and such and crack will always propogate on a grain size level (through or around) this is true no matter what the size of the sample. Where you have to be careful is on shallow hardening steels like 1095 where on the large samples the actual core is diffusion hardened which will not be the case in the thin cross sections of knives.

If you recall, Crucible's original data made a very poor case for using the steel and was if anything counter-productive in supporting the steel's toughness claims.

The origional data noted that the toughness was the same as 154CM and similar steels which would be expected as the carbide volume is the same as is the martensite structure as they all have similar levels of carbon in solution. It was then revealed that the transverse toughness was much higher and this (without any effort to sustain correlation) was suddenly promoted as proof of its toughness. Of course if that data was representative then it would be several times tougher than those steels which it is not because that direction is never loaded in knives in use. Have you ever seen a blade split from tip to choil in use?

At the same time you ask us to accept that accademia is implicitly honest...

Never said that either, it is in fact known that the peer review process in general does little at times to validate data because of the internal levels of politics and quite frankly ignorance of many reviewers. However, data by salesmen and data by researchers is on a different level, it is really naive to argue otherwise. Neither you nor anyone else here does reasearch for their other products on a similar manner. If you are searching for a contractor do you just ask the guy and take his word for the quality of his work and materials or do you check and ask for references, look for independent checks (BBB, etc.). Yeah, everyone responsible does.

-Cliff

 

[Jerry Hossom]

L6 is a low carbon and low carbide steel, similar to 12C27M which you much criticised, yet the same L6 is much stronger (and still tougher) than A2 a much higher carbon and carbide volume steel. You do not see the contradiction here between this materials data and your comments about carbide volume and strength?

L6 is hardly similar to 12C27M. For starters it has over 40% more carbon than 12C27M, and little chromium. 12C27M is stainless. In the range of Rc58-60 it is no tougher than A2, and I don't know where you got your strength numbers, but since L6 isn't one of the steels I was referring to it doesn't matter. It might well be stronger than A2, but it is CERTAINLY stronger than 12C27M. This is a complete change of subject, since L6 is not among the steels we were discussing and nothing like the steels we were discussing, e.g. 12C27M, 420HC and 440A.

Yes, everyone does, anyone that has used large blades anyway. It is straightforward to note that the impact toughness of the shock and similar steels correlated very well to their ability to resist cracking in blade use. Harley for example recently notes this with bainite vs martensite L6. Now which one do you think the standard impact tests will favor strongly.

If everyone has this data, tell us where it is. I use large blades and I don't have it. Impact toughness (at least as measured by Charpy testing) may relate to blade toughness, but it tells us nothing about a tendancy for plastic deformation. Nor does it tell us anything about a steel's usefulness in knives since toughness may be completely at odds with other attributes we like such as edge strength and edge holding. S7 is tough, but is not a great knife steel for those reasons. Even the sword makers aren't very fond of it, and they are less concerned with edge holding than most knife users would be.

Actually no, your own photographs likely show that because you have deformation of the edge bevel as a whole while the very edge (micron level) is still aligned. Anyone who has chopped knotty wood will have seen at one point the bevel as a whole deformed/turned to the side while the edge is still crisp and sharp. Of course the actual deformation will occur on slip planes and such and crack will always propogate on a grain size level (through or around) this is true no matter what the size of the sample. Where you have to be careful is on shallow hardening steels like 1095 where on the large samples the actual core is diffusion hardened which will not be the case in the thin cross sections of knives.

You're saying edges don't deform, as in rolling? You're suggesting a crack will form somewhere besides the edge?

Never said that either, it is in fact known that the peer review process in general does little at times to validate data because of the internal levels of politics and quite frankly ignorance of many reviewers. However, data by salesmen and data by researchers is on a different level, it is really naive to argue otherwise. Neither you nor anyone else here does reasearch for their other products on a similar manner. If you are searching for a contractor do you just ask the guy and take his word for the quality of his work and materials or do you check and ask for references, look for independent checks (BBB, etc.). Yeah, everyone responsible does.

You're suggesting knifemakers don't do research and that you do?

If I were searching for the behavior of jet airplane wings having structure A under load B, would I most likely want to talk with the people at Boeing or a young PhD from a small university who studied something completely unrelated to aeronautics? Whose advice am I going to heed before I board the plane?

Cliff, to suggest that knifemakers necessarily lack intellectual credibility and/or integrity because they're knifemakers is a little off the edge. Do you really think we're all in this for the money...?

 

[hardheart]

I'm putting this out there wrong, I know it... let's say you have 440C at 59 Rc, and 3V at 59 Rc, HT'd correctly. Charpy test both of them, which fractures/breaks the piece, and the numbers are slightly different.

Test their hardness, which checks strength, which is resistance to deformation, if I understand this (probably not). They're both 59 Rc...

So, if you do something to one blade, and it doesn't dent/roll, then the other one shouldn't dent/roll (same geometry), right? Now, one may chip when the other doesn't, but wasn't that the difference in toughness?

I guess I'm saying, if a steel dents, make it harder, if it then chips, choose a different steel. Does that sound right?

 

[cds4byu]

This post got started way back when by saying that a Fiskars hatchet was of medium quality, and could chop lots of wood.

My experience is that Fiskars hatchets and axes are lots better than medium quality. Granted, I've never tested a custom forged hatchet, because until recently I never knew such things exist. But of the readily available hardware store hatchets and axes, Fiskars have outstanding performance. I've never bought a better axe at a hardware store; in fact, it's not even close.

Now Fiskars axes are not beautiful, and I don't really love the plastic handle, even though it's very functional. But in terms of taking and holding an edge, and chopping performance, I find a Fiskars to be really good.

Carl