PM-V11 revisited

I want data... and the reason why

Bill Tindall

If you and Chris forsake your carbon steel blades for PMV11 blades, when they become available, to capture this claimed no cost to sharpening "2X " blade life benefit I will publicly eat crow. But that is not the reason to keep this topic alive. I am satisfied to let history settle this discussion.

Rather:

LeeValley provided data from two tests that are relevant and one test that I don't consider provided relevant data. I am convinced by the Lee Valley data that the PMV11 steel has abrasion resistance similar to A2, and greatly less than say M2. Hence, if plane blades dull significantly slower in use then it can only follow that the significant wear mechanism for plane blades is not abrasive wear. The two apparent remaining choices are adhesive wear, something improbable with a material as weak as wood rubbing on steel, and corrosive wear. In the world of woodworking it would be a woodworking "Nobel Prize" to discover another significant wear mechanism for plane blades. The considerable work of Kato and Kawai and others didn't discover anything different from abrasive wear in their work. But then they didn't look at corrosion resistant steel per se. Their blade lives were predicted by the amount and composition of hard carbides present, which of course affect sharpening.

The benefit of understanding something is that it enables one to predict performance of the untried, which can lead to improvement or break through. If corrosion resistance is important "we" should be looking at high chrome and nickel cutlery steels for plane blades, similar to the path the knife makers took to achieve corrosion resistance. Here-to-for it has been assumed that to get longer blade life that harder carbides were required, for example vanadium and tungsten. Maybe the lesser hardness of chromium carbide is good enough and the resulting corrosion resistance becomes the winning attribute. This revelation would refocus on where in the world of steel one looked for improvement.

It will not be hard to detect the claimed 2X difference, or not. Simple microscopic examination would reveal such a large difference.

Re: PM-V11 revisited

Joel Moskowitz

I am confused. When someone tell me something holds an edge longer than something else I am interested but when the test is generalized to "A2" or "01" I lose considerable hope.

If you look at Brent Beach's plane iron tests of several years ago all A2 blades do not perform the same.

O1 has a very very wide range of performance from tools made by extraction, to drop forging, or to hand drawn out steel with incredible edge life and ease of sharpening.

What confuses me is I don't know if we are talking about a tools that works very very pretty well compared to other tools made by extraction, or if it really holds it own compared to the best stuff out there.

Excellent point you make

Bill Tindall

It is easy to loose track of the fact you remind us of. The same metal composition, which determines it name, can be both manufactured and heat treated to yield widely different properties. In the case of PMV11 the manufacturing is revealed- powder/particle metallurgy and this process has predictable beneficial effects. Presumably the heat treating was optimized for best properties. We know less about the A2's.

Re: PM-V11 revisited

Derek Cohen (in Perth, Australia)

Hi Joel

Let me unconfuse you

Yes, A2 steels may well vary. So let me be specific. I compared Lee Valley/Veritas A2 plane blade steel with Lee Valley/Veritas PM-V11 plane blade steel.

In my experience, this A2 steel is excellent. It rates the same as LN A2 steel on BB's site. The Hock A2 is given a very slightly better rating but not significantly so ("28" to "25"). The only steels that Brent rates above A2 are the D2, M2 and 3V. O1 does not feature at all among these steels (scores a "10"). Based on my data, the performance of PM-V11 would place it at the level of M2 and 3V on Brent's list (that is, a score of about "50").

Link to Brent's results: http://www3.telus.net/BrentBeach/Sharpen/bladetest.html

Now the point of PM-V11 steel is an easy-sharpening steel - which you would definitely not consider D2. M2 or 3V to remotely resemble! - and that holds an edge significantly longer than A2. Well, I do (as does Chris Schwarz) consider that PM-V11 meets this target.

Regards from Perth

Derek

Re: I want data... and the reason why

Derek Cohen (in Perth, Australia)

If you and Chris forsake your carbon steel blades for PMV11 blades, when they become available, to capture this claimed no cost to sharpening "2X " blade life benefit I will publicly eat crow.

Bill, you are quite safe. I shall not be divesting myself of all my "other" blades for PM-V11. Why? Because the "other" blades are still doing a decent job, and also because it would cost a small fortune to exchange all of them. It is just not a reasonable challenge.

However, I shall replace a few selected planes, and if I need a new replacement blade or a blade for a plane build, then there is absolutely no doubt what this blade will be.

Regards from Perth

Derek

Re: PM-V11 revisited

Joel Moskowitz

I don't think Beach tested any forged 01 and the difference in edge life between rolled 01 and Japanese full 9 yards is staggering .

While I don't actually disagree about D2 being a "hard to sharpen steel" I have never found it so. There is a concept in Japanese tools that different tool respond differently to different stones. I once had a mess of D2 blades to sharpen and I used my normal criteria - the closest stones and went at it with Superstones. What a horrible process. After 5 minutes I was tired, frustrated, and ready to kill someone. Fortunately I remembered to switch to other stones I switched to Choseras (nortons also work well on D2) and finished the job in a minute or two.

Others recommend diamond for various materials. I also hollow grind everything.

Now that I am carving a lot I am also sharpening or at the very least stropping a lot and if you carve you quickly realize that carving and keeping your carving tools sharp are a joint operation that happen at the same time in the same place.

The best A2 I have ever used is a Holtey iron that was amazing and very easy to sharpen. The next best is a hock blade that is really really wonderful, None of the other brands I have have lasted long enough in my tools to justify any accolades.

I am looking forward to this new alloy finding its way out to users very soon.

Re: PM-V11 revisited

Derek Cohen (in Perth, Australia)

Joel, I agree with all you write. No arguments. However I must point out that one of the criteria for PM-V11 was easy sharpening. With the exception of my Japanese blades, which are easy to hone on simple waterstones, for D2 and 3V and other PM steels I have diamond paste on hand. I have Sigma stones as well, and they do a decent job on M4. However I do not believe that we can refer to these as "easy sharpening" equipment (they may make the job easy, but they are a required upgrade). Chris Schwarz used oil stones when he tested PM-V11. I used Pro Shaptons.

Regards from Perth

Derek

Re: I want data... and the reason why

TomD

Except that the knife crowd has spent the last 30 o 40 years running away from high chrome steels were edge retention was the benefit.

Your analysis is interesting, Bill, but maybe it oversimplifies. What if there is a component to A2 that is present in it, does something we have no interest in, and the removal of which is a benefit to sharpening ease, but does not affect wear. Waterproof levels of chrome sometimes seem to do just that. Something that from the hand tool perspective is an "impurity". A2 is not a steel optimized for the sharpening and edge holding. It has a number of other compromises built into it. So I do not think that dreaming up another steel that works better when the optimal characteristics are simplified actually pushes the boundaries as you are suggesting. I would also agree with Joel that testing reveals there is not a straight line relationship between sharpening wear, and tool wear. That may be the correct model, sure sounds more convincing that corrosion, but there just seem to be other variables in there.

Re: PM-V11 revisited

Joel Moskowitz

My carving tools all get sharpened on oilstones. I just don't think anything I actually use is hard to sharpen - if it was I wouldn't use it. That this new steel can be sharpened on oilstones is a nice thing.

Re: PM-V11 revisited

david weaver

Beach tested an eskilstuna iron (berg brand), which is probably forged, as well as a clifton iron. Both fared reasonably well, I think. The way they fail looks to me (just by sight inspection) to be tilted more toward what I'd consider "pure" wear and less toward random damage. (I'm sure there will be people who don't like that term, but whatever).

I prefer irons that fail just from "pure" wear because the surface they leave is nice all the way through not cutting at all.

At one time, Beach had numbers for a tsunesaburo blue steel iron, also, and I think I'd rate that at about the limit of what we'd consider carbon steel. It was somewhere around the eskilstuna iron.

I'd consider the tsunesaburo iron to be the best iron I've ever used (for stuff we commonly use in the US), as long as one is willing to use a cap iron properly with it as it is thin. It is easily maintained without a grinder just with a 1000 stone and a finish stone. And it's definitely longer lasting than any of the vintage irons I have by an amount that can be noticed in general use (those vintage irons being a bit inconsistent, but even the best in my use - the ones that fail with "pure" wear).

Anyway, just adding that I don't think there is much room to go above the knight O1, the eskilstuna and the plain hitachi steels when it comes to durability of a steel that's fairly plain.

Kato and Kawai on this topic

Bill Tindall

In a paper only partially translated by us they investigated wear on various plane blade steels and found the phenomena you describe. While the "divots" could be chips from one cause of another, in their case they occurred with steels that had large "grains", AKA crystals of alloying metals.

When a steel melt is cooled it takes a long time for a large melt of steel to cool. If there are alloying elements present- vanadium, tungsten and the like- during the long cooling time they can grow large crystals of carbides and other structures. When these "chunks" are located at an edge they can become dislodged and leave a divot. The Kato and Kawai paper show pictures of this effect and the blade leaves tracks as you describe. In fact they got the best surface from carbon steel which lacks these large grains.

Enter the advance of the particle/powder steels. Crucible Products calls these steels "particle" while others use the "P" for "powder". In any case the steel melt is sprayed to form fine droplets of molten metal, which because they are tiny, cool instantly. This quick cooling precludes the growth of large crystals or phases of the alloying metals. This powder is then reformed under pressure into a solid mass by some magical process that includes processes that resemble forging, that does not enable the crystals to grow larger. The result is a fine grained metal that contains amounts or kinds of alloying metals that otherwise would product a large grained steel. TaDA! Now the steel companies can make steel alloyed with elements that improve all sorts of properties- toughness, grindability, abrasion resistance, toughness, etc- yet do it with a fine grained steel that preserves these properties at a fine edge.

Re: Kato and Kawai on this topic

david weaver

I was encouraged looking at the 3v results on brent's page. Exactly what you described was my first reaction to powder metallurgy when I heard that the powder would be something on the order of microns. If it is on the order of microns and uniform, then it shouldn't have the same faults that some cheap HSS has and that some A2 irons have (the best A2 irons I've played with, and in one case tested, did not exhibit any release of particles, and they dulled like a good carbon steel iron, but lasted longer than any carbon steel iron I've gotten).

At any rate, George Wilson constantly has said to me, and mentions on SMC also that he favors carbon steel irons that will just barely let the best quality vintage files catch. I'd presume that this is probably very high 50s hardness. I've gathered that in choosing irons around that, he is picking the hardness where the edge toughness is good enough such that the failure is generally by "pure" wear, instead of as chipping.

I agree with him, though I have had harder irons that resisted chipping, I don't mind sharpening carbon steel.

The tsunesaburo iron is a marvel, though, because it shows that same tendency to stay together at the edge very well, but it is also very hard, and at the same time, the lamination is very thin and the mild steel backing combined with it (presume it's mild steel, or at least some other steel that doesn't get to the same hardness as the edge) makes it so that it takes the same time to waste away the primary by hand or walk it to the grinder.

To a T when I was testing the A2 irons in my early days (they are all approximately the same hardness), the irons that resisted chipping out lasted the longest by far. The chipout is devastating to edge life.

I noticed Joel's comment about not being that impressed with A2, I don't know if he had some that were the "bad" ones we're describing, because the "good" ones far outclass vintage carbon steel irons and nearly all new ones in terms of edge life.

In my testing, the new Lie Nielsen iron I had was the best of the bunch, I think purely because that particular example didn't release anything from sharp to entirely dull. It cut almost 1750 linear feet of hard maple 2 thousandths thick before I could no longer tolerate the fact that the shavings literally had hair like suede (it was still cutting the shaving at that point, though. The irons chipping out had given up not long after 1000 feet or so, and as they had chipped out fairly early, I'd have found their results to be unacceptable for a smoother).

Re: Kato and Kawai on this topic

Joel Moskowitz

When I said "didn't last long" I meant that didn't last long in the plane - that is at some point I swapped out the iron for something else and never looked back. Might have been edge retention, quality of cut, ease of sharpening with the media I was using at the time. I don't remember. While I have nothing against the hobby of looking for the ultimate edge but I figure the current set of irons in the planes I actually use, are most excellent and will last me the rest of my life and then some.

CPM 3V

Bill Tindall

You will not chip this stuff. In fact the problem with sharpening it is that the wire edge is so tenacious that it sometimes persists long after experience suggests it should be long gone. A magnifying glass is a must.

I once advocated it for scrapers on the lathe forum (it is exceptional) but when I was met with a hostile response I retreated to less hostile ground.

Re: Kato and Kawai on this topic

David Weaver

I guess everyone has a different perspective. I'd consider it fairly pedestrian, and good for plane irons if you're *not* chasing the ultimate edge.

I never met a non-faulty iron that I didn't like, though. From the vintage irons that are soft enough for a file to just get a grip to the HSS irons in the mujis that really are a wonder themselves (I would call those chasing edge retention, but they do it at a price less than a carbon steel iron).

Anyway, most of what we do is unnecessary, all the way down to building furniture. I guess we all just have to pick how we're going to entertain ourselves.

Re: I want data... and the reason why

Wiley Horne--So. Calif.

Hi Bill and all,

The data should prove extremely interesting. And I don't doubt for a moment that data will confirm what LV has told us, since LV will have done mondo amounts of testing before staking its reputation on this steel.

Bill said, " In the world of woodworking it would be a woodworking "Nobel Prize" to discover another significant wear mechanism for plane blades." I agree, maybe even a real Nobel prize (i.e., without the quotes around it).

But maybe the answer is not so mysterious. We've been talking about O1 and A2, and that the new PM steel sharpens easier than A2 but wears better. Generally, it is the amount, type, and distribution of carbides that determine wear resistance, including both sharpening difficulty and edge durability. Now if you look at the carbide formers (beyond carbon) in the steels we are referencing--and I'm looking at Crucible Industries' definition--O1 has 1/2% each of chromium and tungsten, for a total of 1% alloy carbide formers. A2 has 5-1/4% chromium, 1.1% molybdenum, and 1/4% vanadium, for a total of 6.6% alloy carbide formers.

So from O1 to A2, we go from 1% alloy carbides to 6.6% alloy carbides. That's a big jump. And yet A2 still only has 1/4% vanadium, which is the premier carbide for wear resistance and edge durability. A2 seems to have taken on a heavy total carbide burden, for the actual amount of wear resistance achieved--6 times as much as O1, but it ain't 6 times more wear resistant. How much good is all that chromium accomplishing in A2?

Do you think it is possible that LV's new PM steel is something like O1 plus a Goldilocks amount of vanadium (ju-u-u-u-st right), such that it still has much less total alloy carbides than A2, but it has more efficient carbides. And perhaps hit just the right balance between total carbides and type of carbides that, indeed, it sharpens about the same as A2 but has more edge durability? Say, by having more vanadium, but less total alloy carbide.

In summary, to believe LV's claims (and I do!), do you really have to postulate a Nobel Prize-level breakthrough in materials science? Or could it be just a matter of being smarter in selecting the carbide amount and mix.

Perhaps LV is the first to make a carbide selection optimized around cutting wood, rather than optimized around some aspect of metal forming and stamping.

Wiley

Re: Kato and Kawai on this topic

CStanford

Mujingfang make horned planes like ECE and Ulmia:

http://www.mujingfang.com/t/eng/p2.asp?ItemClass1=Woodworking+Tools+Series&ItemClass2=European-Style+Bench+Planes

Re: I want data... and the reason why

Warren in Lancaster, PA

I have been thinking along the same lines as you, Wiley, that there is an awfully big jump in chrome, especially, between O1 and A2 and possibly a lot of uncharted waters in between. If people were designing steels for hand tool woodworking, they might like to try a whole range of chrome percentage (like 0.9, 1.6, 2.9) between the 0.5 of O1 and the 5.25 of A2. And then test another cluster around the most promising percentage.

I don't know that anyone is designing steels for chisels, however. A2 was certainly designed for uses other than woodworking. If I read the reports correctly the "PMV-11", chrome unknown, was not designed for chisels either, merely picked out of a group of steels that were already in production and designed for other uses. Just targeting steels with intermediate chrome or vanadium like you suggest might have been cheaper. It appears to me that the batch sizes for making this stuff are so large that they discourage any real experimentation. And maybe the Lee Valley steel orders for chisels and plane irons are still so small that they are just riding on the coattails of some other industry.

One other thing that is unclear to me is who the target user is for these new tools. Beginner, professional, amateur, dilettante?

What was the reason

Richard Jones

for the hostility? That doesn't sound like most turners that I know.

I believe there's a difference between a burr and a wire edge.................

If someone of repute said that CPM3V was the bee's knees for scrapers I'd be all over it, no ego here, just like good results.

Rich

Re: Kato and Kawai on this topic

david weaver

they do, and they're excellent planes if you can tolerate sharpening them. I have two of them and use them pretty regularly.

You could hardly buy a good quality dry tropical wood for a plane body for the price of one of the planes.

If you have the occasion to work something that is hard on carbon steel (like dimensioning a cocobolo infill), the mujis are almost magical. You can dimension an entire panel plane blank without resharpening, something that you stop on 5 or 6 times to sharpen with A2 or more with carbon steel.

The difference is a little less in regular wood, but they still last very long and they're a favorable light and comfortable type of plane (the continental type) to use.

discussing your thoughts

Bill Tindall

"And I don't doubt for a moment that data will confirm what LV has told us, since LV will have done mondo amounts of testing before staking its reputation on this steel" ......What LV has revealed is abrasive wear data, reasonable obtained in my opinion, and, wear data on a relative scale with no clue as to how big the steps are between entries. Furthermore, the wear data is from an experiment with several substantial differences from typical planing. I believe the "wear" test more challenged the toughness of this steel than typical planing wear. Unless there is LV data I have not seen we do not have any wear data from LV that provides any quantitative comparison of A2 vs PMV11 for planing typical North American wood under typical conditions. I would expect Elliot and/or Beach to publish such data if LV does not provide it.

"Generally, it is the amount, type, and distribution of carbides that determine wear resistance, including both sharpening difficulty and edge durability. " This is my understanding from what I have read.

Carbide chemistry- This is not a topic that I know much about other than to say that your analysis is likely not sufficiently complicated. In A2 there is more chromium that can be accommodated by 1% carbon. Iron also forms carbides. Composition will determine what can form while processing will determine what will form. I suspect it is quite involved to predict the actual carbide content of a steel form its bulk composition.

"Do you think it is possible that LV's new PM steel is something like O1 plus a Goldilocks amount of vanadium (ju-u-u-u-st right)" In a word, no. This steel is exceptionally tough (LV chisel test). I suspect its composition will be complex, but trivial to determine by anyone motivated to do so. I also suspect that processing, the particle metallurgy and who knows what else, is a significant factor in determining performance.

"Perhaps LV is the first to make a carbide selection optimized around cutting wood, rather than optimized around some aspect of metal forming and stamping." Now you may be onto something. Abrading steel with wood may be fundamentally different from abrading steel with pointy hard particles, or not. Kato and Kawai studied dulling and silica in the wood was an important factor. The wood specimen acted like a dilute Arkansas stone.

When something does not make sense- less dulling easier sharpening- doing the work to understand the apparent paradox often leads to a new fundamental understanding to the topic at hand. Which, in turn, often leads to even better improvements. Which is why it is worth keeping up with this topic as new data becomes available.

Re: I want data... and the reason why

Rob Lee

Hi Warren -

A couple of quick answers.

PM-V11 is a custom order (mill run lot) - not tied to any industry. There are literally thousands of orderable steels from many suppliers - expecially tool steels.

We have no target market for this steel - it is another choice in the arsenal. It will certainly be a more appropriate choice in some applications (and for some people) than others.

Cheers -

Rob

Re: CPM 3V

david weaver

What is the finish level where it persists? 1 micron diamond on steel?

more

Bill Tindall

The incident was not recent and it involved an accusation that I was trying to sell lathe tools based on exaggerated claims which apparently threatened or annoyed some. I haven't and don't sell anything. Try it and come to your own conclusion.

3V is extraordinarily tough. In its hardened state it can still be bent and then straightened without breaking. Don't try this experiment with M2. I did and the results were not pretty. It therefore follows that a rolled edge on 3V is resistant to breaking off. In 3V one has both toughness and high wear resistance. I like it for lathe tools and have made many from this steel- scrapers, skews, bedans. If I had a milling machine I would have made gouges.