i wonder who here has the gumption...

question

Bill Tindall, E.Tn.

Disclaimer: I don't know anything about Japanese chisels or Japanese woodworking procedures. So this is a question born from ignorance....

Why are these chisels made so hard and therefore brittle? Related question, how are they used that this hardness does not show up adversely in their work?

Re: question

Wiley Horne

Hi Bill,

Most likely answer is that the smith’s customers were working in needle woods. Soft wood, hard steel. That’s the context Japanese tools developed and evolved around. You could also imagine a relationship in the old days, where the smith knew his customer, and the customer might ask for and get particular properties to suit the need. Some customers might add a little temper, just like David did. It’s easier to add than subtract.

Certainly in Japanese planes, the tradition is not ‘works out of the box’. Final fitting was, and is, done by the customer to suit himself. Would not occur to the maker that the customer would not know how to do this.

Wiley.....speculating

Re: question

Orlando in So. Fl.

You're not really speculating too much Wiley. I agree with you that in the old days (1st generation) would tailor their products to their customers. However, some of these customers worked with Japanese soft, medium, and hardwoods depending on their focus thus the different levels of tempering/heat treatments. Today (3rd generation) longer adhere to this way. Their way is to make a good product for the NA and European markets where the customer is not as knowledgeable as those who are in Japan. So QC in forging, heat treatments, tempering, finishing is guided by how many chisels they can make to meet the demands of the markets which in the end means profits. Wholesalers also add to this new trend for they will claim that certain products are of top quality made by one blacksmith in order to turn a profit. Case in point Matsumura chisels have been attributed to one blacksmith working all day in his smithy putting out all types of chisels for worldwide distribution. It's not possible for that to happen. Same thing with Koyamaichi, who BTW I have a chisel whose tang veers to the left and thus, not aligned, 3rd generation Tsunesaburo (still makes a good product), Fujihiro (although Chutaro Imai's top of the line chisel is made of sword steel), Iyoroi. Don't get me wrong, these brands are good for the hobbyist, but in Japan the professionals stay away from them.

It is my understanding that, in Japan, it is understood that the end user is responsible for setting up his own plane and chisel (the professional grade chisel hoops need to be deburrred, have a chamfer filed on the top and bottom before setting them in the handle (which is not hammered and soaked) the set into the handle with a mallet then mushroomed with a steel hammer). Same thing for the planes. I had to set up my planes because they are definitely not ready out of the box.

The two pictures show the difference between a professional grade chisel and one that is not. On the left is a mentori oiirenomi by Fujihiro and on the right is a professional grade kakauuchi oiirenomi made by an 84 year blacksmith. Look at the lamination where the soft steel (jigane) meets the hard steel (hagane). The professional grade one is straight and the hard steel is folded up evenly on the soft steel on the sides. On the Fujihiro the line that separates the two steels is not straight and the way the hard steel is folded up over the soft steel is inconsistent. This is one of the difference between professional grade tools and those that are mass produced. The professional grade blacksmiths are becoming a dying breed in Japan. Even some chisels marketed here and in Europe as being Japanese are being made in China.

BTW, the kakauuchi style has square sides while the mentori has beveled sides. This was the style Hidari Ichihiro who is one of Japan's revered chisel blacksmiths.

Beyond wiley and Orlando's answers..

David Weaver

...sounds like Orlando has been reading from or talking to Stan Covington!!

I have seen conflicting information, and there are regions in japan where chisels were different styles, finishes and maybe even hardness to some extent. From use, and speculation as a user, I would guess:

* the smiths figured that professionals were buying chisels and would rather temper back

* the use of soft woods by a lot of carpenters made it desirable to get the highest sharpness and hold that, with less challenge to the chisel edges the way we use them in hardwoods. In an era when finishing stones were often natural, the harder the chisel, the finer the finish

* there may have been a pride thing with blacksmiths in trying to chase high hardness and reasonable toughness just as a matter of skill (just talking to japanese people, even young people, you get a sense of burden on them, to stay in line and do their best. Maybe the internet and ease of getting outside of the culture will ruin that).

I find just about anything good to be really good. I don't buy the uber expensive chisels because nobody will want them if you temper them back some, but they will be better chisels if they're tempered.

There's also a lot of subjective semi-religious stuff, even among experienced dealers, about what's better than what else, and I'd imagine that a true test would get rid of some of it, but people who have a religious attachment to something always have an excuse when results don't fit, too. Japanese tools are no different (for example, the feet planed records are not held by simple carbon steels, but there are a lot of folks, I believe Stan is still in that camp, that believe forging can be done so well that a simple carbon steel will outrun an alloy steel. It's easy to disprove, though. The simple carbon steels do seem to me to have a better balance of tip of the edge holding and sharpenability).

Then, there's just easy pickings stuff that's false there. For example. swedish chisels are considered to be easy sharpening (japanese chisels with swedish steel). They're just softer when they're spec'd to be easy sharpening, but there are a whole bunch of people running around talking about how easy sharpening swedish steel is. If their Assab K120 chisels were hardened to 65 or 66 like they claim to be, they wouldn't be so easy sharpening. Temper them back to 63 or so, they hold a great edge and are much easier to sharpen. The natural stones tell you these things very quickly.

What Orlando mentions about Stan is sort of Tokyo sentiment. The harder the better and if reality doesn't accommodate it, push for it, anyway. I suspect professional use may be a little more "accommodating" in different areas, and I don't know what the range of professionals is, as I've seen videos of professional carpenters preparing beams with makita portable power tools and perhaps doing the end work with hand tools (it wasn't included in the videos).

I suspect that the tool manufacturing has gone the same way - to more modern process, more forging in shaped dies and less freehand to meet an aesthetic sooner. You can speculate on and on if you're like me buying a bunch of stuff and passing it through - what's worthwhile (using good materials and not breaking rules making things) vs. what is a little fruity to me ("forged five times for this or that".) I fail to believe that any of that really overwrought stuff amounts to much other than making presentation tools or tools for westerners.

Orlando mentions koyamaichi chisels - those chisels are made in dies (Forged by pressing?) and grinding fixtures, so a lot of the hand work is jigged instead of freehand. They're a reasonable price, but then the guy making them gets to work faster, and perhaps sometimes doesn't check straightness that well (or maybe the handle fitting wasn't done with as much care). KI's chisels in dies, the ones that I had, were full hardness, the finish was a little less pretty than more expensive chisels, but they were functionally as good as anything I've had.

Final thought, though - once accommodated, I do seem to be able to get decent toughness at a little bit higher hardness with japanese chisels than western chisels. But, I suspect it's the ingredients (the steel in the edge, the fact that they are forged and not just stamped out of premade material - except the really cheap ones) and basic metalsmithing, and that the same thing could be done elsewhere without too much trouble.

Re: question

Warren in Lancaster, PA

I find that I can tolerate a large range of hardness in chisels. I think chipping and folding results from poor technique, both in sharpening and in use.

A dozen years ago a friend gave me some plain carbon chisels that were tempered at 375 degrees F, which is up there with the hard Japanese chisels. (Tempering at 420 yields hardness of 63 and 460 yields 62, so these would be 64 or so.) I have no problem using them on high density hardwoods. I can use them on a domestic hardwood like Maclura pomifera or a tropical hardwood like Ochroma pyramidale.

I prefer chisels more on the softer side, partly because of ease of sharpening. We can learn to handle these chisels as we did 200 years ago.

Stan Covington wrote this five years ago:

Some of the best-cutting and most durable laminated plane blades I have ever seen were made in Sheffield England in the 1800's, and branded "Cast Steel." The West simply abandoned the techniques still used in Japan.

Re: question

Miedema

"On the left is a mentori oiirenomi by Fujihiro and on the right is a professional grade kakauuchi oiirenomi made by an 84 year blacksmith."

Someone else who fell for Covington's nonsense. The guy wouldn't know a professional grade chisel if you hit him on the head with it. I've tried his Nagamitsu brand chisels made by Nakajima and they're really nothing special. I have some old oiirenomis that were made over 50 years ago and they run circles around Covington's Nagamitsu brand.

leads to another question

Bill Tindall, E.Tn.

run circles around Covington's Nagamitsu brand.

I don't know anything about Japanese chisels. So take this question in this context; it is not a snarky spirited question. What does "run circles " mean? In my bumbling ignorance of Japanese chisels I don't know what property difference(s) would lead to this statement.

In western chisels I could describe substantial differences in the ergonomics of various brands and some differences in steel. So what separates Japanese chisels other than hardness?

A question to Warren

Bill Tindall, E.Tn.

"I find that I can tolerate a large range of hardness in chisels. I think chipping and folding results from poor technique, both in sharpening and in use."

It would seem from the discussions the past few months that mechanical damage, as opposed to abrasive wear, is the mode of dulling lots of people experience with chisels. We have been treated to many stunning microphotographs proving this point.

What technique and sharpening differences do you employ in cross grain material removal (dovetail waste, for example) to avoid what seems to be a common problem for most, if not all, other chisel users?

runs circles

David Weaver

it's some nonsense, more or less. All of the good chisels are about the same and the difference in what users like is generally difference in properties of the chisels and how they're sharpening.

Stan is fascinated with high hardness, and i'm sure his sharpening accommodates that.

Of the good modern and old chisels that I get fished out of auctions in japan, I see no real difference unless chisels are defective. You could sort them by hardness and each sorted set would be almost indistinguishable.

The chisel that I pictured, I'm pretty sure I could set it up easily to do a day of joinery without resharpening and then resharpen out of sight. I recall from odate's book that at least in some circles, it was important to be seen as working quickly (as consideration to the customer) and not sharpening in front of them (you're to be doing their work, not caring for your tools).

But old or new, when the stock is good quality, they've had any kind of forging at all and they are in a reasonable hardness range, they're all about the same.

Stan likes what he likes and is very opinionated about it. I tend to believe that anyone who believes there's a huge difference between die pressed forgings and freehand power forgings, etc, when the same material is used (whether it's the old tools are better folks or the new tools are better folks) have little objectivity or aren't looking at the real factors causing difference in performance.

Tasai, for example, has a reputation for making chisels very easy to sharpen. If they are easier to sharpen, either the alloy is different from reheating it over and over (i.e., less carbon) or the chisel is just a touch softer. Tasai does spend a lot of time on aesthetics, and that sells well to the US and europe. I'm fairly sure that if I had kept my kamaji iyoroi chisels (which are considered a step down), I could change the label on them, talk them up, and people would love them. "they're easy to sharpen and chip less!!"

Stan's opinions..

David Weaver

stan has a lot of opinions, but some of them stretch past what would hold up in testing.

375 degrees F tempering is about 62 hardness in O1, 400 is 61-62 if the steel was brought to a high temperature and quenched quickly.

460F is about 59 hardness.

The same figures work for 1095 (if not wanting oil hardening steel).

The really soft cheap hardware store japanese chisels are somewhere around 61/62 (english friend hard his iyoroi mortise chisels tested and they were about that on a versitron, but they are softer than any japanese chisels I've ever used, perhaps set soft since they were for mortising - really easy sharpening).

Their bench chisels are harder.

When you get into main line japanese chisels that are actually 64-66, they are harder than I can get any acceptable edge behavior out of. The one I sent steve is borderline (that was an old file, so probably not much different than White 2, except maybe not as clean - and not laminated). It's probably 63 hardness.

Last comment -stan considers japanese chisels just a touch softer to be junk, but glows about the sheffield chisels that are probably 61/62 hardness. Even the $65 iyoroi wrought backed chisels that I have are quite a bit better than any english chisels that I've used. They couldn't quite be cut on oilstones, but could be polished by them. That kind of contradiction exists in what he says - that a chisel that holds an edge half as well as one of the modern mid grade chisels is OK, but the chisel that's better is not (because it's modern and supposedly not well regarded).

If you had steel close to as hard as the average good quality japanese chisel, though, it would barely be cut by the king stones (they're too soft and it just pulls them apart and isn't abraded fast enough by the soft slurry), and you couldn't do anything but burnish them even with a slurried washita. I tried rolling the tip yesterday on a chisel that I tempered at 325F and it's still so hard that I could sharpen the very tip at a steep angle on an oilstone for a minute and still not have much of a visible bevel. The hardness is a completely different league and would be offputting to anyone using oilstones.

Re: runs circles

Miedema

Stan certainly has a high hardness fetish. It explains his love for Kiyotada. Funny thing is he still thinks Kiyotada is the best thing ever even though his earlier work was very hit and miss. Don't get me wrong, Kiyotada isn't to be snubbed at (his late period work that is) but it really is a soft wood chisel just like all the other old Kanto blades. There are far better choices for European hard woods.

I can easily tell the difference between a mass produced, die forged chisel and a hand forged chisel just by how it feels on my stones and in use as well. A die forged chisel doesn't have the same grain refinement and this affects how sharp it can get which in turn affects how it cuts.

Hmmm, Tasai. Let's just say he's the least talented of the Yamada clan.

Re: A question to Warren

Warren in Lancaster, PA

I could write all day on this. I have written for more than a decade on this forum condemning harsh abrasives for sharpening. I have often used the term brash. A harsh abrasive makes deep scratches which are difficult for subsequent steps to remove. If harsh stuff is used throughout, one is left with a jagged edge which is vulnerable to damage. A smooth edge with shallow scratches is strongest. I use Arkansas stones to polish the edge and a clean leather strop to finish the edge. I use these methods because of the results I get. Not surprisingly, these are traditional methods. People were not any dumber in historic times.

Maybe I will write some more later.

Re: Stan's opinions..

Miedema

I have a full set of Sukemaru oiirenomis (that I bought long before Stan even knew about the brand) and they're all on the high end of the hardness scale at 66+HRc. I've never had any problem getting good edge behaviour/life out of them. And mind you, I use these in European white oak as well.

I tend to do my rough sharpening on a King 800 and 1200. I have no problem getting a burr in a relatively short amount of time. Your problem could be where you focus the pressure.

Range of hardness

Warren in Lancaster, PA

I looked at a chart for 1095 for my hardness figures; maybe you looked at another chart. So what?

The point is that I have chisels by the same maker that are very different in hardness, and yet I am able to use either one without chipping or folding. The difference is easily noticeable in sharpening; one is extremely hard.

Some talk as if there is a narrow range of acceptable hardness, a little harder and the chisel chips, a little softer and the chisel will bend. I don't find this to be the case; a large range of hardness is acceptable. I prefer the softer chisels because they are easier to sharpen and I get excellent performance.

Re: runs circles

David Weaver

you can tell the difference between hardness on your stones, or change in the composition of the hagane (repeated forging chasing carbon out could make it seem easier abrading).

The only thing kiyotada's chisels need when they're overhard is an hour in the oven at 325F. That's the case for most overhard chisels. They're about 25 tempering degrees away from being great in hardwoods.

Press forged laminated japanese chisels being far different than the kind of one strike inexpensive western tools that get shaped and then trimmed in a press (and are made out of barely high carbon steel). Angle, hardness and edge treatment the same from one chisel to the next and the feel on stones has much more to do with how thick each part of the lamination is and what the jigane is made of.

Forged steel doesn't feel different on stones at the same hardness - stones abrade, they don't test toughness.

If you watch the hammering process of a japanese smith making chisels, the heat is not too high, and the rest of the process itself is exhausted only shaping the tools. There is no significant process other than that. If a press forging is overheated for long and allowed to stay like that for a long time in the open atmosphere and the tool suffers, that's a different thing, but the same would happen if a hammered tool was overheated a bunch.

You don't have to change logins from your Nico login to post here.

The truth of all of the tools is that people who think they see something really different from one maker to the next, or one stone to the next (be it stones selected from $150 used stones on buyee vs. $4000 stones sold marked up 3-4x by dealers), the person who thinks they're seeing things is probably not much of a craftsman because there's almost no difference between any of it. It's immaterial.

To be chipped or not to be chipped

Winston

One person might see this chisel and say that the edge isn't chipped.

Another person might look at this picture and say that the edge has chipped.

It shouldn't be a surprise that these are the same chisel. It's easy for people to talk past each other when it comes to chipping and folding of edges.

For me, after looking at this stuff at both normal and magnified scales, it's clear that any inconsistency in the reflection at the edge of a blade must be due to folded or chipped metal. What else could it possibly be?

That said, I could understand if someone else doesn't call it chipping or folding until it happens at a larger scale. The problem is, without pictures or some other point of reference, we don't know exactly what someone means when they say that their edge hasn't chipped or folded. If two people are using the same words to mean different things, and they never figure out what the other means, this can lead to endless talking in circles.

Re: Stan's opinions..

David Weaver

Did you have them tested on a versitron?

I doubt they're 66 if they can be finished in any reasonable time on natural stones or have a wire edge raised quickly on king stones unless the hagane is about as thick as a sheet of paper. The fascination with spec sheet hardness is kind of sutpid, but it sure is stylish.

All hard chisels will work fine in hardwoods unless they're over the limit of taste (as in almost untempered or untempered) if the tip is accommodated or the whole bevel chased steep enough. Chisels that are over the limit will chip in sharpening or light paring, even at high angles. Most become world class tools with 25 degrees more tempering temperatures.

The difference between ouchi(1), sukemaru or anyone else is just in what hardness they choose and what type of finish or shape they make chisels.

Re: A question to Warren

Bill Tindall, E.Tn.

David uses an Ark stone and he still sees mechanical damage if the bevel angle is not increased to where it doesn't occur, something over 30 degrees. Hence, a natural stone does not appear to be the key to avoiding mechanical dulling. So is a high bevel angle (or Unicorn Profile) the way to avoid mechanical damage, and the only way?

Repeating the question

Bill Tindall, E.Tn.

What are you doing that avoids the damage others commonly see?

Re: Stan's opinions..

Miedema

I didn't have them tested but I know at what temperature they're tempered. At 110C it's impossible they're softer than 66HRc.

I can go from a binsui to a suita with my Sukemarus and remove the binsui scratches in less than a minute. I must say I prepare my suita with an Atoma 400 and I don't rinse of the sharpening milk (don't know what else to call it). This speeds it up a lot of course. I don't know why you're having problems but a good quality Japanese natural stone shouldn't have any problem cutting a high hardness blade.

There is some discretion

David Weaver

I can use diamonds at every step and as long as the last step is suitably fine and cleans the edge of any damage, the tool being used will last longer than natural stone edges because of the level of refinement.

If I were to take a diamond hone and then just strop at the tooth by hand and then expect it to last as well as an oilstone, it doesn't.

It's to the discretion of the user to figure out what works, either by testing things, or doing comparison in actual work with two different tools, then continuing to be curious as time goes on to see what else may affect things.

For example, early on, I had an A2 iron from hock, and a high carbon steel iron from hock. I tested the two irons in actual use by planing for a period of time and through a certain amount of work, and the A2 iron lasted noticeably longer. It just did, every time. More panels. But the panels weren't rough sawn, they were machine planed and just needed to be flattened and i thicknessed them some to suss out whether or not A2 was worth the trouble. I would've said A2 lasted 33% longer based on those tests - 4 for each 3 that O1 did from the same maker.

I could make a statement based on that, but rather than do that, I continue to wait to see more. A2 has to be set very steeply to stop chipping, but even when it's set steeply, it still outlasts O1 in ideal conditions. When you start planing rough wood, though, I don't get the same experience in total time spent, and I gradually went away with it.

In stroke testing last year, I found about the same, but this time, 25% more edge life for A2. I didn't like the condition of the edge during that 25%, but it lasted longer.

I don't think it would last any longer cutting across hand sawn end grain or working try plane work or dealing with knots (in fact, I just unicorned the LN iron that I have, the last A2 iron I have for planes, and it didn't fare well on the dime store pine. It chipped easily, even accommodated. That wood is filthy and it eventually chipped everything in the smoother, leaving only the ward iron in the try plane seeming to behave normally. But if I turn around and use the ward iron, for example, it'll last about 75-80% as long taking thin shavings as does my best O1 effort. It'll be nice and uniform. This kind of test is idealized, though - in certain work (especially heavier work) the ward in a wooden plane beats V11 in a metal plane. BTDT and got the wrong idea about V11 earlier on.

Back to the diamonds - the key to using harsh abrasives is separating angles so that the fine abrasive can remove enough edge. That's pretty much it. Nobody will hone a full bevel with harsh abrasives at every step and ever do enough work to remove a huge pad of metal to make up for what's going on at the edge, but bias the angles, and it becomes very easy. The quality of the edge is viewable under a microscope when freshly honed (where getting things perfect is easier with diamonds on wood than it is with any black or trans oilstone) and then at every step along the way. Carbon steel wears evenly enough that minor defects are worn off and the area where they wear is more gradual. The condition of the edge when done is very predictable and takes little work to refresh. To the extent that others don't abide the same, then the method just needs to be changed to accommodate them. There just aren't that many absolute truths.

Re: Stan's opinions..

David Weaver

I've seen and used hundreds of chisels, and I've made tools and quenched everything from file steel to V11.

And I've seen about 200 japanese natural stones, from antique picks to hatanaka stones.

If your chisels sharpen easily from binsui to suita, they're not 66. Tempering temperature isn't the only variable. Heat before quench can have a great effect, as does transition temperature. If one smith heats chisels to a higher level and transitions them faster or for longer in the quench, or both, the chisels will be harder to start, and tempering will bring them down from there.

if the chisels are partially quenched, or quenched at a lower starting heat, which is common in water quenching (to avoid warping and cracking), then the tools will not attain full hardness. They'll be 3 of 4 points off.

Binsui will generally not cut steel that is 66 hardness. It will skate as they are almost entirely silica.

The thing that nobody wants to admit is that they like chisels that are 63 hardness instead of 66. When it comes to actually doing work and resharpening, I like 63/64 rather than 66.

I refurbished two chisels this weekend that were so hard that they graded aluminum oxide paper. They were probably actually 66 or a little bit more.

The difference between what I'm telling you and what you're telling me is experience. I have occasionally taken some tools or traded with folks who have access to a versitron. This is a risky thing to use on japanese tools as you have to be willing chance cracking a tool if they're really at 66 hardness. Most good sharpening chisels are not, and I have seen iyoroi chisels that strike as low as 61 average. They are still good chisels in the hands of a skilled user as long as the defective ones are tossed out. The basic models are ugly, though.

By the way - 110C does not do anything to any white steel or k120 or anything of the sort to relieve hardness, and it's probably not enough to add any considerable toughness.

The two overhardened chisels that I mentioned above are nearly untouchable at 300F (about 150c) by any natural abrasive. Binsui would have no chance.

Make a few tools. You can hammer some (I have hammered some knives and chisels at low temperature. The starting stock and then the heat temp and transition speed has a lot more to do with the finished product than anything else). Heat a few in dim light to different eye colors, quench them in the same medium for different times and from different starting temperatures and to different completeness. You can get good enough to start a low temperature quench and make a usable tool without tempering, but it's risky. I have two different O1 irons that i made when I was experimenting with keeping heat low - they are only about 60/61 hardness. I've never tempered them and their behavior is fine. I doubt it could be done consistently. It's more useful to go a step or two past critical heat to have room to work and then temper back and hit a target dead on.

i experienced the same...

David Weaver

..then other considerations need to be made beyond that - V11 will look back at you with even the tiniest amount of edge damage that remains invisible with other chisels.

A look under the microscope sort of confuses what's seen based on reflecting light vs. the size of the damage. Thus, I used microscope pictures in the article, and generally always do.

I don't have some smart setup that will take slices of a 3d edge, though, to look face on with the V11 and see why the shape of the damage seems to be a little bit different.

Re: Range of hardness

David Weaver

The hardness figures were pretty far off and I have a lot of experience with different japanese chisels - i don't care too much about the tempering schedule differences, more the sentiment that something tempered at 375F would be close to japanese chisels in mid range hardness (As in, if you bought 30 vintage chisels off of japan's version of ebay and then created a midline after throwing out the three hardest and softest).

They are much much harder than 1095 or O1 tempered at 375.

I agree with the sentiment about hardness range. I have an ideal, but that's different than a range that can be reasonably accommodated with experience.

For oilstones and western tools, the older sheffield chisels are in my ideal range, as are the newer AI MK 2 chisels. I would be surprised if my sorby chisels struck 58, though - they are probably close to that and with monstrous accommodation, which is what the unicorn is, they're usable without issue. The slightly overhard chisel that I sent steve is probably 63 hardness based on its behavior on stones. It could come down a notch, but it's still usable. It needs to be accommodated a little for the opposite reason.