12c27... why not more love?

[sodak]

on the first point, i agree... facts are facts. Some steels will last 15-20 times longer at maybe only 2-3 times the price and that is a great deal if the primary focus is edge holding. That being said it's a balance and my original point of this whole thread was that if a particular steel isn't going to take abuse or cannot be resharpened by some of the barbarians that end up as owners, I'm the one they complain to when they say "you're knife is a piece of junk, i chipped the blade opening a crate and i can't resharpen it. That's why I sometimes favor the simpler steels and purpose choose them in many cases. Great for me that they are cheaper as well and great for the most likely abusive end user.

On your second point, unless a customer is a little more informed and requests a particular steel, knowing it's limitations and benefits I only use simpler steels for the army guys too and for the same reason. You think wives and kids are hard on things in the kitchen, you gotta see some of these guys with their knives. It's amazing what a simple knife can be asked to do outside the realm of cutting... and even more amazing how sour someone can get when they break their tip off or chip the edge trying to do something rediculous.

I suspect if I had to replace knives due to abuse to the general public (or soldiers ), I would be very hesitant to use anything other than 5160 at 1/4 thickness or greater. I'm picturing the old Samsonite commercials with the gorillas in the cage... I was in the Army also, and would cringe when someone wanted to cut metal banding around a Conex with a knife.... Insert tip, pry up - why did this thing break?

 

[pinnah]

I look at it this way:

Is any given Mercedes a higher quality car than, say, a Civic? Yes, I don't know too many people that would argue otherwise. But the Mercedes is going to take more effort and more money to maintain annually than the Civic. And for some people, not only is that not worth the extra cost, it's just not worth the headache either. So which is truly the superior car? It's completely subjective based on what your expectations and end uses are.

Similarly, is something in a high carbide steel worth it? Someone with money and time might say yes. Someone who wants value and low effort upkeep might say differently.

I think this is close and probably true for many people - the sort who simply buy cheap and don't maintain their knives. There's no dispute that happens all the time. I'll bet that more than 85% of SAKs sold never get sharpened before they are lost or destroyed. Just a hunch.

But it's also true that there is a huge group of people who favor fine carbide steels because they give an altogether different performance balance. For these people, the right analogy might be between a Mercedes sedan and a Ford F-150. I don't care how nice the Mercedes is or how fast it is. It doesn't have the hauling capacity or the ground clearance of a sedan.

Ankerson is dead spot on regarding this point. It's about carbides. They give the basic trade-off. Edge retention vs ease of sharpening. This has nothing to do with cost.

 

[pinnah]

I try and stay realistic on my views and based on what my extensive testing has shown over the years, being realistic is the key I think.

The only time I usually start posting in a thread is when things start going sideways and away from reality or just bad information starts to get spread around like it's facts.

I think we are just trying to keep it factual.

Ah... Which facts?

We used to have a saying when I was in product management. Our opinions, while interesting are irrelevant. The only thing that is relevant are market facts.

Market facts are different from engineering facts. Market facts are facts about end users. Market facts are about understanding the customers real needs - understanding the use case. Confusing engineering facts with a market fact is what we used to call "The Geeks Fallacy". The geeks fallacy is that a product that is the best according to some metric will be the best in a market. It's just not true.

This is particularly true in performance engineering when there are very different use cases involved and vary different techniques. Cycling and skiing are two places outside knives where I've dealt with this but a common is cars vs trucks.

Here is a (qualitative) market fact... There are Bladeforum sub-forums that are chock full of knife enthusiasts are well acquainted with newer medium carbide steels but prefer fine carbide steels. The Becker, Buck and Outdoor sub-forums are the ones that come immediately to mind. These people aren't uneducated. They aren't lousy at sharpening knives. They don't lack experience with these medium carbide steels. They have a noted and persistent preference for fine carbide steels.

Moving away from my marketing side to my engineering side, the engineering issue is the carbides. A consistent thing I hear from people who prefer fine carbide steels is that they put a higher value on ease of sharpening (and many may not have access to adequate sharpeners).

It's amazing to me that this continues to be this controversial.

 

[calc]

But it's also true that there is a huge group of people who favor fine carbide steels because they give an altogether different performance balance. For these people, the right analogy might be between a Mercedes sedan and a Ford F-150. I don't care how nice the Mercedes is or how fast it is. It doesn't have the hauling capacity or the ground clearance of a sedan.

Why are you telling me this? I specifically asked about AEB-L and mentioned that there are a few applications I think it'd fit well, I'm aware of the performance balance of steels. I've consistently said that low/fine carbide steels have their place and absolutely did not simplify it down to cost alone.

 

[pinnah]

Why are you telling me this? I specifically asked about AEB-L and mentioned that there are a few applications I think it'd fit well, I'm aware of the performance balance of steels. I've consistently said that low/fine carbide steels have their place and absolutely did not simplify it down to cost alone.

I'm sorry calc. I must have missed what you've said in other places in the thread. Too busy to catch everything. Just responding to the analogy that was quoted (and which I largely agree with). Just looking to build on it.

Sorry for the misunderstanding.

 

[calc]

I'm sorry calc. I must have missed what you've said in other places in the thread. Too busy to catch everything. Just responding to the analogy that was quoted (and which I largely agree with). Just looking to build on it.

Sorry for the misunderstanding.

That's alright, I might have just implied it in this thread but I've for sure expressed it elsewhere as well. I agree with what you're saying.

For example, my wife and I cook quite often, and we recently switched out a mixed set of Victorinox and ESEE/Becker kitchen knives for Tojiros. Now, the VG-10 on the Tojiros holds an edge longer than the steel (not sure what) of the Victorinox set and also of the 1.4116 of the ESEE/Becker set. But here's the thing: it only held longer for me, not my wife.

My wife, bless her, is not gentle with knives. She sees a knife as a means to an end and nothing more, so if she can accomplish something with the knife, she's going to go for it. Bone? Countertop? Who cares, something needs to be cut and it needs to be cut fast - so it is.

As a result, for her, VG-10 doesn't last as long with a serviceable cutting edge. She tends to stick with paring/utility and carving sized knives, whereas I largely stick with the santoku and gyuto; although the latter typically experiences more chopping (pretty vigorous chopping at that), the former actually has more chipping that I need to touch up more often.

So for me, VG-10 was an upgrade. However, for my wife, it was actually a downgrade.

The typical response to that sort of complaint is that proper technique needs to be used to avoid chipping and that you simply need to learn how to use your knives. But there's the rub: the ability to process food quickly is a positive attribute, and to her, more important than frequency of sharpening. She would gladly give up some wear resistance for toughness if it means she can be a little more quick and carefree while cooking.

So we know what works best for us, which is all that matters in the end.

 

[sodak]

[...]
Ankerson is dead spot on regarding this point. It's about carbides. They give the basic trade-off. Edge retention vs ease of sharpening. This has nothing to do with cost.

There is no tradeoff between edge retention and ease of sharpening. That's the whole point. You can easily use this for $6.

http://www.homedepot.com/p/Norton-6-in-Tool-and-Knife-Sharpener-87933/203204893

 

[chiral.grolim]

... we recently switched out a mixed set of Victorinox and ESEE/Becker kitchen knives for Tojiros...

The typical response to that sort of complaint is that proper technique needs to be used to avoid chipping and that you simply need to learn how to use your knives. But there's the rub: the ability to process food quickly is a positive attribute, and to her, more important than frequency of sharpening. She would gladly give up some wear resistance for toughness if it means she can be a little more quick and carefree while cooking.

So we know what works best for us, which is all that matters in the end.

Again, I doubt this has anything to do with steel formula, it's a matter of edge geometry coupled to technique. Maximizing performance and durability is part of edge geometry. If an edge is experiencing failure, slight adjustments in angle or edge thickness can often solve the issue quite quickly. Generally chopping knives and those subject to greater stress will have a stouter edge-angle than slicers and may be thicker behind the edge as well. My in-laws abuse their Wusthof knives (57Rc X50CrMoV15 steel) and end up with terrible edges... but altering the edge-angle from <10-dps to 20 enhanced durability substantially while having no noticeable (to them) impact on cutting efficiency since the edges remained fairly thin at the shoulder. The knives still blunt when they bang them on plates, etc. but chipping is much less common.

Can you measure the edge geometry of each knife with a caliper and report back? E.g. measure the thickness of the blade at the "edge-shoulder" (where the primary bevel meets the edge bevel). If you can't find the edge-shoulder on a knife, measure the bevel height of a knife that does have a shoulder, and then measure the thickness of the "zero-grind" knife at the same distance back from the edge. With similar edge geometry, the primary difference between the 57Rc and 61Rc blades should be a reduction in blunting (via rolls, compression) of the harder blade. The 61Rc blade will require greater stress to induce a chip than is required to deform the 58Rc edge.

I replaced my wife's Wusthof 4" parer with a different 60+Rc AEB-L knife from the maker Tim Johnson mentioned above, it is at 15-dps and ~0.010" behind the edge and has become her primary kitchen knife for months now. In that time I've repaired 2 rolls in the edge on a butcher's steel, no chips as of yet.

 

[Ankerson]

Ah... Which facts?

We used to have a saying when I was in product management. Our opinions, while interesting are irrelevant. The only thing that is relevant are market facts.

Market facts are different from engineering facts. Market facts are facts about end users. Market facts are about understanding the customers real needs - understanding the use case. Confusing engineering facts with a market fact is what we used to call "The Geeks Fallacy". The geeks fallacy is that a product that is the best according to some metric will be the best in a market. It's just not true.

This is particularly true in performance engineering when there are very different use cases involved and vary different techniques. Cycling and skiing are two places outside knives where I've dealt with this but a common is cars vs trucks.

Here is a (qualitative) market fact... There are Bladeforum sub-forums that are chock full of knife enthusiasts are well acquainted with newer medium carbide steels but prefer fine carbide steels. The Becker, Buck and Outdoor sub-forums are the ones that come immediately to mind. These people aren't uneducated. They aren't lousy at sharpening knives. They don't lack experience with these medium carbide steels. They have a noted and persistent preference for fine carbide steels.

Moving away from my marketing side to my engineering side, the engineering issue is the carbides. A consistent thing I hear from people who prefer fine carbide steels is that they put a higher value on ease of sharpening (and many may not have access to adequate sharpeners).

It's amazing to me that this continues to be this controversial.

I was talking about performance and some of those fairy tails that seem to go around now and then.

I think we all know what those are and all of them are complete BS, so that's what I mean about reality.

For the most part I have used almost all of the steels that are talked about and or tested them over the past 35 years so I have don't have any delusions about what the steels will do or not do.

Lets just say there are steels that don't have anywhere near the edge retention that some people think they have while others don't just fall apart like some would have people believe and leave it at that.

 

[Ankerson]

I suspect if I had to replace knives due to abuse to the general public (or soldiers ), I would be very hesitant to use anything other than 5160 at 1/4 thickness or greater. I'm picturing the old Samsonite commercials with the gorillas in the cage... I was in the Army also, and would cringe when someone wanted to cut metal banding around a Conex with a knife.... Insert tip, pry up - why did this thing break?

We used to do the same thing with our knives, cut metal banding with our K-Bars and a lot of it.

Not like we had tin snips handy.

 

[calc]

Again, I doubt this has anything to do with steel formula, it's a matter of edge geometry coupled to technique.

I don't know why you're repeating it to me. Even if I wasn't an engineer by trade, it's not a hard concept to understand.

Additionally, edge geometry should be optimized for the steel type and cutting media. You can't really separate the two completely, they're intrinsically tied. It's like analyzing weight loss and saying "I don't think it has anything to do with your diet, it's a matter of exercise".

Generally chopping knives and those subject to greater stress will have a stouter edge-angle than slicers and may be thicker behind the edge as well.

Can you measure the edge geometry of each knife with a caliper and report back?

I no longer have the Victorinox set. However, I can assure you that the Victorinox line is much thinner than the Tojiro line - thin enough to where they actually flex like fillet knives. Not as extreme, of course, but in a similar fashion.

Additionally, I sharpen them at a the same angle that I sharpened the Victorinoxes. When I microbevel the problem is slightly alleviated but still present.

With similar edge geometry, the primary difference between the 57Rc and 61Rc blades should be a reduction in blunting (via rolls, compression) of the harder blade. The 61Rc blade will require greater stress to induce a chip than is required to deform the 58Rc edge.

Both blunting and chipping will reduce cutting ability. I'll take slight blunting over extreme chipping any day.

The fact of the matter - in my experience with these two specific brands and steels - to attempt to match the cutting ability of the thinner Victorinoxes, the Tojiros would need to be dropped down to an angle at which chipping negates the increase in edge retention that VG-10 gives me over the Victorinox steel. Now, with proper technique, can this be alleviated? Yes, to some extent. But the ability to allow the user to be a bit sloppy, to rush a bit, to use the same knife for several tasks instead of switching out to avoid edge damage, these are all positives where actual work is concerned. So if this is your primary concern - which it is for people like my wife who value efficiency - then the Victorinox steel is indeed the better steel for this application.

I'm not saying anything out of the ordinary here, I don't know what you're trying to argue with. In any case, the Tojiros are nice knives, and I like VG-10 as a steel, especially for kitchen knives. I would buy them again in a heartbeat. But low carbide steels have their place, even aside from matters of cost, which is exemplified here.

 

[rustyrazor]

We used to do the same thing with our knives, cut metal banding with our K-Bars and a lot of it.

Not like we had tin snips handy.

still don't! lol. the thing I've noticed about knives in the military over the years is: they clean stuff with em, chop with em, dig and hack roots with em, cut down small trees and clear brush with them. Often baton firewood, make shelter and traps for food and prepare a fire then spark a ferro rod with them. As well, they prep food, use them as cooking utensils and sometimes eat with them when they can't find a spork. As mentioned they pry stuff, cut things you shouldn't and use them to throw at stuff when you're bored... and I don't know anyone who's ever used one as a weapon. why carry 40 tools, when you can use one thing for so much? the knife was the original multitool.

P.S. and 80% of the time they'll blame the knife if they chip it or break the tip, treating it like a wrecking bar.

 

[Vedenant]

still don't! lol. the thing I've noticed about knives in the military over the years is: they clean stuff with em, chop with em, dig and hack roots with em, cut down small trees and clear brush with them. Often baton firewood, make shelter and traps for food and prepare a fire then spark a ferro rod with them. As well, they prep food, use them as cooking utensils and sometimes eat with them when they can't find a spork. As mentioned they pry stuff, cut things you shouldn't and use them to throw at stuff when you're bored... and I don't know anyone who's ever used one as a weapon. why carry 40 tools, when you can use one thing for so much? the knife was the original multitool.

P.S. and 80% of the time they'll blame the knife if they chip it or break the tip, treating it like a wrecking bar.

This is The Truth!

And here in Nordics, most guys use Moras or assorted other puukkos to do it , not something that is advocated in the bushcraft forums.

 

[chiral.grolim]

I don't know why you're repeating it to me. Even if I wasn't an engineer by trade, it's not a hard concept to understand.

...

I no longer have the Victorinox set. However, I can assure you that the Victorinox line is much thinner than the Tojiro line - thin enough to where they actually flex like fillet knives. Not as extreme, of course, but in a similar fashion.

Additionally, I sharpen them at a the same angle that I sharpened the Victorinoxes. When I microbevel the problem is slightly alleviated but still present.

The bolded is why I keep responding: flexibility has to do with stock thickness, not edge thickness. I have a stiff Buck boning knife (0.090") with a thinner edge (0.010) than my Marttiini fillet knife (0.040" stock, 0.020" edge) both sharpened to the same angle. The Marttiini is more flexible because it is thinner... but not behind the edge. The buck is the better slicer and is also more durable because of the stronger steel. A lot of budget kitchen knives are built in similar fashion - thin stock with a simple edge - while a lot of more expensive brands are built of thicker (stiffer) stock but are ground to a finer (thinner) edge for improved slicing ability. What I wondered is if the Tojiros are the same way. Durability of an edge isn't about stock thickness, it's about edge thickness and angle. Anyway, I am surprised to read of the VG10 difficulties if indeed the edge is as robust as the 1.4116 blades which is why I asked. I did not mean to insult your intelligence.

 

[Twindog]

The bolded is why I keep responding: flexibility has to do with stock thickness, not edge thickness. I have a stiff Buck boning knife (0.090") with a thinner edge (0.010) than my Marttiini fillet knife (0.040" stock, 0.020" edge) both sharpened to the same angle. The Marttiini is more flexible because it is thinner... but not behind the edge. The buck is the better slicer and is also more durable because of the stronger steel. A lot of budget kitchen knives are built in similar fashion - thin stock with a simple edge - while a lot of more expensive brands are built of thicker (stiffer) stock but are ground to a finer (thinner) edge for improved slicing ability. What I wondered is if the Tojiros are the same way. Durability of an edge isn't about stock thickness, it's about edge thickness and angle. Anyway, I am surprised to read of the VG10 difficulties if indeed the edge is as robust as the 1.4116 blades which is why I asked. I did not mean to insult your intelligence.

This is so true. I have a small Tojiro chef's knife of 0.076 inch stock with a 0.020 width at the edge shoulders. But my favorite chef's knife is a Kumagoro hammer finish 5.3 inch utility petit guyoto. It's stock is thicker at 0.13 inches at the base (however with a full distal taper), but the edge width is just 0.009 (hard to measure because the edge height is so small. But it is the slicing champ. It's made with some kind of low-carbon V2 steel at 62-63 Rc. It is the only knife I freehand sharpen on an extra-fine diamond stone. It sharpens extremely fast and easy, and the edge geometry not only helps on resharpening, but it also slices extremely well. Rusts when you look at it, however.

 

[calc]

The bolded is why I keep responding: flexibility has to do with stock thickness, not edge thickness. I have a stiff Buck boning knife (0.090") with a thinner edge (0.010) than my Marttiini fillet knife (0.040" stock, 0.020" edge) both sharpened to the same angle. The Marttiini is more flexible because it is thinner... but not behind the edge. The buck is the better slicer and is also more durable because of the stronger steel. A lot of budget kitchen knives are built in similar fashion - thin stock with a simple edge - while a lot of more expensive brands are built of thicker (stiffer) stock but are ground to a finer (thinner) edge for improved slicing ability.

Technically, it depends on a few things - thickness, stiffness of the material, etc. You keep oversimplifying things to a point where you're, at best, misleading. Edge thickness does in fact have an effect on flexibility. If a knife is flat ground, as most kitchen knives are, that thin edge doesn't just magically appear. Material has to be removed to taper down to that measurement, material from the whole height of the blade. So you can argue about the level to which it's a factor, but you cannot state that it doesn't have an effect at all.

In any case, I mentioned it because it demonstrates how they're drastically different knives. The difference between the two is obviously apparent in use. And the difference between between stock thickness and thickness behind the edge isn't exactly nuanced. I measure this quite often:

http://www.bladeforums.com/forums/showthread.php/1214276-Thickness-Behind-the-Edge

What I wondered is if the Tojiros are the same way. Durability of an edge isn't about stock thickness, it's about edge thickness and angle. Anyway, I am surprised to read of the VG10 difficulties if indeed the edge is as robust as the 1.4116 blades which is why I asked. I did not mean to insult your intelligence.

I've previously covered the edge thickness and angle.

I wouldn't say that VG-10 is giving me difficulties, I simply had to adjust my sharpening and reformulate my expectations. Again, I'm not saying one steel is better than the other in a vacuum, I'm saying that one steel is more appropriate than the other for specific use cases with specific knives. And for our use case, going to VG-10 on a select few of ours knives was actually a downgrade.

What we're losing sight of is practicality. Who's the better engineer, the one who designs a product that only a few like to use or the one who designs a product that a great many like to use? For some reason people ITT aren't accepting that both are equally as valid approaches. You can design the best product/system/whatever in the world, but if nobody likes to use it, you missed the most important thing in the design process. Usability is key.

An analogy I like to use is beer. Now, with the advent of craft beer came the inevitable snobbery of macro beer. The prevailing opinion is that craft beer is typically of higher quality than macro beer. But, why is that? Surely, they use better ingredients, have a wider variety of tastes, etc. But how does that invalidate macro beer?

Macro beer tastes exactly how they want it to taste. The quality control, the brewing process, everything about macro beer is technically of high quality. Their variation batch to batch is minuscule to nonexistent and they're extremely efficient at producing it. And, most importantly, the end product is beloved by many.

Just because you don't prefer something doesn't mean it's objectively worse.

For some reason that statement is extremely hard to accept for people like us, people that collect and use and appreciate high quality <insert random thing here>. But just because people don't like to accept it doesn't make it any less true.

 

[pinnah]

There is no tradeoff between edge retention and ease of sharpening. That's the whole point. You can easily use this for $6.

http://www.homedepot.com/p/Norton-6-in-Tool-and-Knife-Sharpener-87933/203204893

Sodak,

We normally agree on a lot of things but will probably need to agree to disagree on this one. I'll try to rearticulate my experiences and what I hear from others but will probably just let it go after that. Two things...

First, there are use cases where that stone, as cheap and readily available as it is, can't be assumed. Bushcraft & military/survivalist teachers often cite the ability to sharpen a knife on crude stones or found objects as a selection criteria. The issue is carbides. They give more edge retention and make it harder to sharpen.

Second, I can sharpen a knife. I sharpen as a means to an end, not as a hobby. I keep my knives hair popping and paper slicing sharp and convexed but I don't treat it as an end unto itself. I have a variety of flat and guided rod systems both with both normal stones and diamond stones. I'm neither a complete sharpening idiot, nor an expert.

When sharpening, I can easily tell the difference between fine carbide steels and my 440C blades. Even with a diamond stone, the 440C requires more passes and more pressure. As we would expect. 440C has more carbides. Not as much as the medium carbide steels like S30V perhaps, but more than 12C27 or 420HC.

One could easily discard my personal experience as a single data point, but peruse the Buck forum or the Becker forum or the Outdoor forum and read the threads on steel selections.... I'm obviously not alone in my experience or opinion. Buck isn't propagating an unfounded myth when they describe S30V on their website as harder to sharpen. That's an opinion formed in their own shop (they report that they burn through grinding belts faster) and one that has been confirmed for a couple of generations of Buck customers has they've provided feedback not only S30V but other larger carbide steels. Again, the issue is carbides. They create a basic trade off between ease of sharpening and edge retention.

This isn't a which is "best" any more than one can pick a best style of car (sedan, sports car, station wagon [best, imo] or truck). "Horses for courses", as they say. I know a lot of deer hunters who prefer the old Bucks with 440C for dressing deer and that makes perfect sense to me. The carbides keep going through hair, hide and meat and sinew and the like. But for EDC... Lots of guys on the Buck forum have a strong preference for 420HC and it's definitely not a cost issue. They spend good dollars on custom 110s, and often use them hard in the field. Cost difference on the S30V blade is a meager $18, which given the cost of a custom is peanuts. They simply have a strong preference for the small carbide steel and the balance of qualities, including the ease of sharpening, is a part of that.

 

[Ankerson]

Depends on what uses to sharpen with in the end.

One or 3 passes on something like a SIC loaded strop or a Ceramic rod or say 30 secs for a touch up when the edge starts to lose bite, steel doesn't matter for the most part, could be 420J2 or S110V, touch ups take the same amount of time in my experience.

The big difference is setting the bevel the 1st time and yes the steels with the higher carbide content will generally take longer than the low carbide steels, that's things being equal (Geometry).

But once that's done it can be trivial to maintain an edge, very trivial.

Things can be as simple or a over complicated as one wants to make them, or as easy or hard as they want to make it.

Now yeah some dude with some old Arkansas stone that his grandfather used goes an tries to deal with something like S30V they will have some problems.

Same problems a lot of people had with 440C a long time ago using the same types of stones, those with SIC stones didn't have those problems and still don't today.

 

[chiral.grolim]

Technically, it depends on a few things - thickness, stiffness of the material, etc. You keep oversimplifying things to a point where you're, at best, misleading. Edge thickness does in fact have an effect on flexibility. If a knife is flat ground, as most kitchen knives are, that thin edge doesn't just magically appear. Material has to be removed to taper down to that measurement, material from the whole height of the blade. So you can argue about the level to which it's a factor, but you cannot state that it doesn't have an effect at all.

The flexibility of the different steels at such stock thickness is so similar that it is irrelevant to the discussion. Flat-ground knives are triangles in their cross-section, the distribution of mass/support in a triangle is weighted toward the spine's thickness to an increasing degree depending on the bevel angles. Like you said, the thin edge has to get there somehow. The effect of edge-thickness on blade flex for a 1" wide blade is so small compared to the stock thickness that, unless the thicknesses are practically the same, the edge-thickness is irrelevant to the discussion. It's like an I-beam (as you should know, being an engineer?) - what relevance does the thickness of the thin inner-portion have on the stiffness of the beam vs the wide edges? In order to begin bending the thinner section, one must overcome the much greater stiffness of the thicker section(s) as stiffness is cubically related to thickness. For example, if the spine is merely 2X thicker than the edge (as in my Marttiini example, 0.040 vs 0.020), that means that the stiffness at the spine is 8X that of the edge - relevance ratio 8:1. If the difference is greater, say 9X thicker like the Buck, then the spine stiffness is 729 X greater than that of the edge - relevance ratio 729:1. This is not "over-simplifying", this is establishing relevance.
You mentioned that one set of blades were thin enough to flex vs the other were not, I simply pointed out that difference has to do with their stock thickness NOT their edge thickness (as illustrated above) and only the latter has to do with durability of the edge. I illustrated the point by giving an example (and another has been given) of thin knives with thick edges vs thick knives with thin edges.

In any case, I mentioned it because it demonstrates how they're drastically different knives. The difference between the two is obviously apparent in use...

..I've previously covered the edge thickness and angle.

I am glad you measure edge-thickness, not everyone gets the idea so I apologize for belaboring that.
The only difference under discussion is edge durability which has nothing to do with blade flexibility or stock thickness, only edge geometry. You mentioned giving each the same microbevel angle but did not provide the edge-thickness of each nor the depth of edge-damage sustained. I am trying to get a clear picture of the edge-geometry of each. Were they the same or not? Giving a 15-dps microbevel to my straight-razor (already <0.005" behind its 8-dps bevel) does not make it more durable than my normal paring knife which, as it happens, is much thinner at the spine and so is more flexible. The paring knife is thicker behind the edge, this allows it to endure more stress (abuse) than the razor - they don't necessarily have the same edge-geometry despite that microbevel because (ab)using the razor-blade in similar fashion to the parer could result in damage beyond the microbevel. My suspicion was that the same was true of your knives - the VG10 blades thinner (and therefore "weaker") at the edge and so more prone to damage despite the same microbevel angle as the others. If the VG10 blades are NOT thinner, or damage was within the microbevel, the point is moot.

I wouldn't say that VG-10 is giving me difficulties, I simply had to adjust my sharpening and reformulate my expectations. Again, I'm not saying one steel is better than the other in a vacuum, I'm saying that one steel is more appropriate than the other for specific use cases with specific knives. And for our use case, going to VG-10 on a select few of ours knives was actually a downgrade.

What we're losing sight of is practicality...

IF the knives have the same geometry and one steel is performing better than the other in a given task, then that steel is absolutely better than the other. If VG10 at 60-61Rc requires a thicker geometry (and correlated lower cutting efficiency) to provide the same level of durability against the stresses it will encounter, it is worse steel 'practically' speaking at that hardness. That's what you mean, right, choosing the right tool for the job? Ceramic blades are capable of taking the finest edges and providing supreme edge stability (hence their preferred use in industrial equipment)... but they can be fragile if "mis-used" and since most kitchen knives are mis-used the practicality of ceramic blades is low for most users (not to mention sharpening concerns). Perhaps the VG10 would be more durable/practical at lower hardness (if toughness increases, which is not guaranteed), but then why bother with it? What would surprise me is if the steel type rather than the hardness and geometry is what is making a difference as I very-much doubt that 1.4116 is all that much tougher than VG10, just softer so that it readily deforms where VG10 (at same geometry) holds firm (hence its use in so many popular spydercos). *shrug* http://www.cliffstamp.com/knives/reviews/deerhunters.html


Back on topic, the abuses to which soldiers submit their knives is so significant that it overshadows the minutely different levels of toughness provided by a lot of steels. To encounter such stress, the maker must provide a strong geometry first and then select a material that can achieve an appropriate level of edge-hardness (>56Rc?) without compromising its durability at the geometry selected. I would guess that 12C27 and 420HC are not as tough as L6 or 5160 or S7, but at the geometry required to sustain the level of stress to be endured, those differences may not mean much practically speaking. These are corrosion-resistant steels and maybe provide a harder edge and a soldier might not see any benefit from selecting Elmax or M390 instead... The comment was made on Jim's rope thread that Spyderco left a lot of edge-retention performance behind when it built knives of premium steels with such thick geometry (>0.020" behind the edge)...

 

[calc]

Nothing misleading in my statement at all and I'll thank you to withdraw that assertion.

If it's not misleading then it's mistaken. I'm not going to lecture you on physics because you feel the need to be the smartest person in the room about something that doesn't actually matter in the big picture of this particular instance.

If you'd like to continue this particular discussion, we can do so elsewhere because it's driving the conversation off topic.

The only difference under discussion is edge durability which has nothing to do with blade flexibility or stock thickness, only edge geometry.

I don't know why you're choosing this particular issue to be pedantic about, I simply said that the Victorinoxes were so thin that they had noticeable flex in them. Now, if you're specifically curious about:

You mentioned giving each the same microbevel angle

I am trying to get a clear picture of the edge-geometry of each. Were they the same or not?

I've clearly said that the Tojiros are thicker behind the edge than the Victorinoxes were. And I've also clearly said that I sharpen them at the same angle. And I've also clearly said that I started microbeveling the Tojiros once we experienced chipping.

My suspicion was that the same was true of your knives - the VG10 blades thinner (and therefore "weaker") at the edge and so more prone to damage despite the same microbevel angle as the others. If the VG10 blades are NOT thinner, the point is moot.

Again, the VG-10 blades are not thinner.

If VG10 at 60-61Rc requires a thicker geometry (and correlated lower cutting efficiency) to provide the same level of durability against the stresses it will encounter, it is worse steel 'practically' speaking at that hardness. That's what you mean, right, choosing the right tool for the job?

Of course that's what I mean. That's why I've explicitly said it several times.

What would surprise me is if the steel type rather than the hardness and geometry is what is making a difference as I very-much doubt that 1.4116 is all that much tougher than VG10, just softer so that it readily deforms where VG10 (at same geometry) holds firm (hence its use in so many popular spydercos).

I don't know the hardness of either. I'm not saying this about VG-10 in general, I'm simply saying this about Tojiro's VG-10.

I'm not quite sure what we're disagreeing about here.

I'll also point out that I'm not the only one who has experienced chipping with Tojiros. And the Victorinox line is used in quite a few professional kitchens in part because of their minimal upkeep (and, of course, low cost).

So I'll just leave it there.

EDIT: I'll tell you what: I'll sharpen up some of the utility knives to eliminate the microbevel and in a month or so I'll upload pictures of the chipping. Some of it is visible to the naked eye, very noticeably so. We can pick the discussion back up then.