Secondary bevel on Japanese Mortise chisels?

[Harlan Barnhart]

I have several Japanese mortise chisels that are approx. 5/8" in the cross section. It doesn't seem right to use a secondary bevel on a Japanese chisel, but an edge blunt enough to last is not acute enough to penetrate. Anyone out there use these? How is it done?
-Harlan

[Don C Peterson]

I'm a heretic, but I put a secondary (micro) bevel on all of my chisels (both western and Japanese). The sharpening goes faster and the edge is more durable. Your work and sharpening methods are bound to be different, so I'd just suggest that you find what works for you and don't worry about tradition for tradition's sake.

[Pam Niedermayer]

Your instinct to not install secondary and/or micro bevels on Japanese chisels is, IMO, correct, they kind of subvert the whole purpose of laminating steel to softer iron. As to your sharpening problems, this may be due to the chisels themselves if they're extremely inexpensive or malformed, or if you aren't sharpening them properly. How about some photos?

Pam

[Don C Peterson]

...they kind of subvert the whole purpose of laminating steel to softer iron.
Pam

Put a secondary bevel or not, it doesn't make any difference to me, but I don't understand the reasoning behind your comment. Care to expand on it?

Here's my reasoning on the matter, feel free to enlighten me if I'm mistaken:

Regardless of the type of construction a more acute angle (given the same materials and heat treating) will do two things, it will penetrate better, and be more fragile. Sharpening the bulk of the chisel bevel with a more acute angle but having a less acute angle right at the very edge seems (to me) to be a pretty good compromise between ease of penetration and durability.

Japanese chisels are typically harder than their western counterparts. This provides good edge retention while the laminated iron (or softer steel) provides resiliency over most of the chisel. However, right at the edge, there is no softer iron to support the steel. And of course it is the edge that is most likely to suffer damage, particularly in a mortising situation. This becomes more of a problem the harder the steel is and has nothing to do with what is used as a backing material for the bulk of the chisel because, as stated above, the backing material isn't there at the edge.

To be sure, work methods can be adjusted to prevent damage, it is thus largely a matter of preference. But I certainly don't see how putting a secondary bevel in any way negates the benefit of lamination. Quite the contrary, to my thinking, and in my experience, it is even more beneficial with laminated chisels than it is for others.

[Chris Friesen]

There are a couple reasons why one might not use a secondary bevel on chisels:

1) it makes it harder to freehand sharpen
2) it makes it harder to use the chisel bevel-down

Item 2 doesn't really apply to mortise chisels of any sort, so item 1 is the only real downside.

As a data point, the English mortise chisels by Ray Iles are ground as you suggest...a 20 degree primary bevel for penetration then a smallish secondary bevel at 35 degrees or so for strength. They suggest just honing the secondary bevel until it gets too big, then regrinding the primary.

[Don C Peterson]

I sharpen all my tools almost exclusively freehand and have had no problems with secondary bevels. I'm not one of those people who insist on precision when it comes to bevels on edge tools though. For me close enough is good enough when it comes to sharpening.

I can see the point about making it harder to use bevel down, but it seems more like a theoretical problem than a real one. I routinely use my Ray Iles mortise chisels bevel down to clean up the bottom of mortises and have actually found the secondary bevel to be pretty helpful. Of course cleaning out the bottom of a mortise isn't exactly a precision operation...

[Pam Niedermayer]

Put a secondary bevel or not, it doesn't make any difference to me, but I don't understand the reasoning behind your comment. Care to expand on it?

Here's my reasoning on the matter, feel free to enlighten me if I'm mistaken:

Regardless of the type of construction a more acute angle (given the same materials and heat treating) will do two things, it will penetrate better, and be more fragile. Sharpening the bulk of the chisel bevel with a more acute angle but having a less acute angle right at the very edge seems (to me) to be a pretty good compromise between ease of penetration and durability.

Japanese chisels are typically harder than their western counterparts. This provides good edge retention while the laminated iron (or softer steel) provides resiliency over most of the chisel. However, right at the edge, there is no softer iron to support the steel. And of course it is the edge that is most likely to suffer damage, particularly in a mortising situation. This becomes more of a problem the harder the steel is and has nothing to do with what is used as a backing material for the bulk of the chisel because, as stated above, the backing material isn't there at the edge.

To be sure, work methods can be adjusted to prevent damage, it is thus largely a matter of preference. But I certainly don't see how putting a secondary bevel in any way negates the benefit of lamination. Quite the contrary, to my thinking, and in my experience, it is even more beneficial with laminated chisels than it is for others.

Primarily as you say, because the soft iron is there to back/support the hard steel, because it is so hard and would otherwise tend to break. With a secondary bevel, the force would be directed away from the soft backer. Second, I often use chisels bevel down, real often, and that, I imagine, wouldn't work as well. Third, I've never had any kind of problem with following the bevels as shipped.

Pam

[Harlan Barnhart]

Your instinct to not install secondary and/or micro bevels on Japanese chisels is, IMO, correct, they kind of subvert the whole purpose of laminating steel to softer iron. As to your sharpening problems, this may be due to the chisels themselves if they're extremely inexpensive or malformed, or if you aren't sharpening them properly. How about some photos?

Pam
They came ground to approx. 30 degree bevels. I can get sharp enough to shave standing arm hair without too much trouble. Maybe my difficulties arise from the fact that I was cutting mortises 1" wide, 4" long and 3.5" inches deep into dry, dry, dry and extremely hard white oak. (Yes, I hear your incredulity all the way from the southern hemisphere Mr. Derek Cohen, but here white oak is considered hard wood.) I eventually evacuated all that I could with a drill and spade bit and cleaned it up with a chisel.

[David DeCristoforo]

Many arguments pro and con. Pam is correct in that it is typically considered a "no no" to put a secondary bevel on a Japanese chisel. But if you look at Krenov's books, you can see many examples of, not just a "micro bevel", but a noticeable "secondary" bevel ground into all of his Japanese chisels. (He would hollow grind his Japanese chisels too.) Toshio Odate recommends doing much the same thing on a much smaller scale by using a curving stroke on the last few passes over a polishing stone, lifting the handle while drawing the blade across the stone. Personally I never do either, preferring a perfectly flat bevel. One way or another, if you can shave with the blade, it doesn't get any better than that...

[Wes Grass]

"With a secondary bevel, the force would be directed away from the soft backer."

"Pam is correct in that it is typically considered a "no no" to put a secondary bevel on a Japanese chisel."


So, for the record, I'm no expert with chisels. But the first statement makes no sense to me whatsoever. Sounds like an old wives tale. Probably started when some poor kid got screamed at by a cranky old Japanese carpenter, or maybe the blacksmith making the chisels, just because he wasn't doing it 'the master's way'.

[Pam Niedermayer]

Whatever yanks your chain, Wes.

[Mike Henderson]

If you're not having success with your present sharpening, I'd try using a steeper bevel angle and a secondary bevel and see how it works for you. If it doesn't work well, all you've lost is some time and a millimeter or two of length on the chisel.

Nothing beats actual use to determine whether a technique will work or not.

Mike

[Sam Takeuchi]

If you see working carpenters here in Japan, you see anything from flat bevel to partially rounded bevel (that is as good as micro bevel) for the reason that the only edge needs to be honed. Honestly this 'micro bevel' thing is quite foreign here. If you break it down, rounded bevel may be classified as micro bevel, but it was something came about from ease of sharpening and/or habit. A lot of carpentry techniques aren't taught from books here, and that includes sharpening and maintenance of tools. There are literally hundreds of ways carpenters treat their tools and they are all ok, because what works for them. I seriously don't think majority of them spend much throught about how hard steel and soft iron interact and such. Just try different things, find what works for you. It's not a precision machine, honing guide isn't widely used here. That means each and every one of them sharpen and hone in their own way.

Sometimes I feel these kind of things get passed on as "this is how it is", when in reality, it doesn't really apply. Don't read into it too much. Try it and find what works for you.

[Derek Cohen]

If you see working carpenters here in Japan, you see anything ....

Thank you Sam. That was a breath of sanity.

You know I love the history of woodworking both West and East. For a hobbiest like myself, there appears to be a spiritual entity that conveys a sense of importance on even the most mundane efforts.

In particular, there is a spirit of mysticism that runs through Japanese tools. The question is, how much is real and important, and how much is our own invention.

I use Japanese chisels a good bit. all are decent but none are expensive by Japanese standards. Run of the mills stuff really. There are Iyoroi bench chisels and slicks, Koyomaichi and Matsumara dovetail chisels.

I ground the sides of the Matsumuras until they were triangles. That did not affect the temper at all (I was careful). I am now going to do the same with my Koyamaichis.

Slowly, all my chisels are being hollow ground on a Tormek (no danger of damaging the temper, and the 10" wheel creates a shallow hollow - the iron backing is hardly affected). Yes it is not traditional. But is makes honing fast and gets the edges very sharp. I have not experienced any failure of an edge due to the loss of support from the reduced backing. This has been ongoing for about two years since I bought the Tormek.

One thing I will not do on any chisel is to use a secondary bevel. This affects the way a chisel may be used - for example, it removes the registration when the chisel is used bevel down (e.g. when paring against a fence). The microbevels I create on chisels are from hollows that are coplanar. This retains the registration for bevel down use.

I do have a set of Kiyohisa slicks on order (from So). I am going to honour the traditional methods with these and work with a flat bevel. Will it produce a sharper edge? Probably not, but we all have the right to believe in what we wish. And who can argue with results ...

Regards from Perth

Derek

[Don C Peterson]

Sam, you post was spot on IMO. I've never understood why so many folks seem to adhere to rigid guidelines in sharpening. A sharp tool isn't the goal, it's a means to achieve the goal, and if the tool is sharp enough for the task at hand, your sharpening method is just fine. Just find what works for you and don't look back.

For beginners the conversation about methods, stones, bevel angles, back bevels, and secondary bevels is necessary so that they begin to understand what sharp really means and some of the methods used to get there, but I would never recommend that anyone adopt someone else's methods in total.

[Frank Drew]

When micro bevels began to be popularized years ago, the suggestion for hand honing was lift the blade to raise the main bevel off the stone by a few degrees for the last several passes. IMO, it's impossible to hone an accurate (flat) micro bevel by hand, without some sort of a honing guide; the human hasn't been born who can establish and maintain a flat micro bevel simply with arm, wrist and hand control. Can't be done, your "bevel" will be rounded, and that will compromise sharpness and accuracy. IMO.

Like some others here, I like a single flat bevel on a chisel, sharpened on water stones; I have good chisels (Ooichi brand, professional quality but not super expensive), and have never found anything about them that I didn't like, and I've used them a ton.

[Frank Drew]

And of course, with very few exceptions (e.g. carving chisels), don't ever put a back bevel on a chisel :eek:!

[Sandy Stanford]

If you see working carpenters here in Japan, you see anything from flat bevel to partially rounded bevel (that is as good as micro bevel) for the reason that the only edge needs to be honed. Honestly this 'micro bevel' thing is quite foreign here. If you break it down, rounded bevel may be classified as micro bevel, but it was something came about from ease of sharpening and/or habit. A lot of carpentry techniques aren't taught from books here, and that includes sharpening and maintenance of tools. There are literally hundreds of ways carpenters treat their tools and they are all ok, because what works for them. I seriously don't think majority of them spend much throught about how hard steel and soft iron interact and such. Just try different things, find what works for you. It's not a precision machine, honing guide isn't widely used here. That means each and every one of them sharpen and hone in their own way.

Sometimes I feel these kind of things get passed on as "this is how it is", when in reality, it doesn't really apply. Don't read into it too much. Try it and find what works for you.

Certainly words of wisdom. I think a man on the job, in any country, whose living depends on wielding tools all day long will take a very direct, less frou-frou'd up path in keeping said tools sharp and in tune. They learn methods that work for them and tend to stick with them.

[Don C Peterson]

...it's impossible to hone an accurate (flat) micro bevel by hand, without some sort of a honing guide; the human hasn't been born who can establish and maintain a flat micro bevel simply with arm, wrist and hand control. Can't be done, your "bevel" will be rounded, and that will compromise sharpness and accuracy. IMO.


Your statement of fact is self-evidently true, it IS impossible to hone a perfectly flat micro bevel by hand. However, I disagree with your conclusion that having a perfectly flat micro bevel is important. It isn't.

I've done both flat bevels and micro/secondary bevels, I've used jigs and done freehand. For me, micro/secondary bevels make sharpening and honing go faster, and using jigs just makes the process take longer without yielding any noticeable benefit.

The bottom line is that each user has to figure out what works for him. Those who say that you should never put a secondary bevel on a certain kind of chisel are, IMO, merely following tradition for tradition's sake. But if it makes them happy to do so, fine. Those who insist on absolute accuracy in their bevel angles and so forth, are again IMO, wasting their time, but it's their time to waste.

Me with my freehand sharpening of micro/secondary bevels probably make some people cringe with my sloppy angles, but they are my tools and if they work for me...

The only real objection I have is when our personal preferences are pronounced to others as if they came from the summit of Mt. Sinai.

Yes, you can put micro bevels on Japanese chisels freehand, and yes, the results can be satisfactory, it all depends on you. You can also use the most expensive jig to hone a perfectly flat bevel and have the results be sub-par.

I gradually stopped worrying about precise angles and jigs as it donned on me that I would rather be spending my time using my tools as opposed to fiddling with jigs and sharpening them.

[Pam Niedermayer]

Perhaps, Don, you can explain to me why it is that NOT using micro bevels is not as personally satisfying as using micro bevels.

Pam

[Don C Peterson]

Pam, I have just found that I can get, and maintain, a good edge faster and easier when using them than if I don't. That's all.

But, since everyone works a bit differently, others may very well find that they prefer straight bevels on some or all of their tools. It is purely a matter of personal preference, not a matter of right and wrong after all...

[Pam Niedermayer]

...But, since everyone works a bit differently, others may very well find that they prefer straight bevels on some or all of their tools. It is purely a matter of personal preference, not a matter of right and wrong after all...

I agree, so why is it that those of us who don't use microbevels and say so are accused of spouting old wives' tales (which to me is pretty much an offensive description in and of itself)?

Pam

[Don C Peterson]

I agree, so why is it that those of us who don't use microbevels and say so are accused of spouting old wives' tales (which to me is pretty much an offensive description in and of itself)?

Pam
OK, this post got a bit long because I am trying to be as clear as I can and at the same time trying my best to not offend, which is easier said than done... But that reminds me of a saying that I'm quite fond of "Anybody can give offense, but only a fool takes it." Anyway...back to the topic...

Pam, it was you who said "Your instinct to not install secondary and/or micro bevels on Japanese chisels is, IMO, correct, they kind of subvert the whole purpose of laminating steel to softer iron." Your statement implies there is something more than personal preference involved and that there is a right answer to the question. This was reinforced when you offered this statement: "With a secondary bevel, the force would be directed away from the soft backer."

My subsequent posts dealt with the reasoning behind your assertion (that a micro bevel on Japanese chisels was a quantifiably inferior choice due to some special quality of the chisel) , and the reasoning behind mine (that given the trade-offs, it doesn't really matter except as a personal preference, and that those trade-offs apply to any type of chisel or edge tool)

There are some definite pros and cons to using a micro bevel:
**note that I use the term "micro bevel" to represent the idea of a "secondary bevel" as well because they are essentially varying degrees of the same thing and there is no agreed upon definition of one as opposed to the other...

Pro:
The edge is less "fragile" because of the greater amount of material supporting it

Con:
The edge is less "keen" since the angle between the back and bevel is greater

Those two are really it as far as I can tell. It is obvious that they represent a trade-off with a rather large continuum between them that can represent a nearly infinite mix of micro bevel sizes and angles. They are also independent of chisel construction (or heat treating) method.

All the other reasons to use or not use them swirl around personal preferences and habits. Some people find micro bevels make sharpening easier, some find them to be more trouble. Even the question about using the chisel bevel down is very subjective.

I think it is interesting to note that Japanese swords are traditionally sharpened with a definite rounding toward the edge, much like you would get from freehand honing of a micro bevel. This was done, as I understand it, to provide maximum support for the cutting edge. I don't know whether the sword making techniques migrated to chisels or vise versa, but they are certainly similar. Yes, the intended uses are very different, but sharpness and edge retention are not completely different ideas when the material switches from wood to flesh and bone...

I have yet to hear a convincing argument that there is some special quality of Japanese chisels that makes micro bevels an inherently poor choice. I'm open to the possibility that a reason exists, which is why I asked you for clarification, but so far all the reasons I've heard just don't add up, with some being utterly nonsensical. Therefore I ascribe the avoidance of micro bevels to personal preference or adherence to tradition (in exactly the same manner as a preference for micro bevels is either a personal preference or adherence to tradition.) Notice that I didn't say that micro bevels are a superior choice for everyone, nor did I say that following a tradition is necessarily a bad thing.

Traditions can be a powerful motivator that helps us feel connected with the past and to a larger community in the present. Which traditions you choose to follow are, once again, a personal choice. I explicitly do NOT equate tradition with "old wives tales" as you imply.

The most convincing argument I've heard is that the materials being worked tend to be different. The bulk of Japanese woodworking has been done in relatively soft woods such as Pine and Cypress. These woods, particularly in cross grain cutting, respond better to more acute angles. They are also not as hard on the cutting edge. I do almost all my work in relatively hard woods. I think this, much more than the type of chisel, is a factor to consider for this question.

The bottom line is that I think that when answering a question such as the OP raised, we should be careful to be aware of and to disclose (which presupposes that we are aware ourselves) whether our answers stem from tradition, personal preference, or empirical evidence.

[Pam Niedermayer]

I know we both understand "IMO." And I do think that not putting microbevels on laminated chisels is the better thing to do. What's more, I gave a reason. And I don't much care what thousands of Japanese carpenters do or don't do. This is simply a logical result of my own.

I also don't hollow grind laminated chisels nor do I use the ruler trick on laminated chisels. You guys can do whatever you please; but my actions are not taken because of old wives' tales or undue influence by alien statists ( :) ).

And if asked again I'll give the same advice. I think these devices subvert the whole purpose of laminating chisels and, in practice, I've found no reason to think otherwise.

Pam

[Frank Drew]

Pam,

What's the ruler trick?

[Wes Grass]

Pam,

Sorry if you took offense at my statement.

If you'll notice, my post was 4 days after yours. And yes, I actually thought about it that long, and really tried to come up with a reason to agree with what you said. I simply couldn't visualize *anything* in engineering terms that could back it up.

The laminate isn't glued onto a backer. It's welded on, creating a homogeneous piece (if done correctly, of course) that would exhibit a gradient of carbon content, and hardness, across it's thickness. In action, the forces created by the wedge of the cutting edge will actually force the laminate into the soft backing, not try to peel it off. And I don't think adding a secondary angle would have any effect on that.

[Pam Niedermayer]

Frank, David Charlesworth described a method to make it easy to make good secondary bevels, to wit, place a small metal ruler under the top of the blade front and sharpen. I suspect there's a more detailed explanation around here somewhere.

Wes, my apology for misthinking on my first post, I read "micro bevel" and thought hollow grind; and I was kind of irritated with myself for that. Still, I see nothing in my work that tells me it might be better to grind/sharpen a secondary bevel. Doing so on a test chisel yielded nothing better. Also, I use chisels bevel down very often for control, and nothing about a secondary bevel sounds attractive in that case.

Pam

[Don C Peterson]

In the books I have, David Charlesworth discusses the "ruler trick" for establishing a back bevel on plane irons, not chisels. And it's really only if the back of the iron isn't flat and would require extensive time at the stone to get it flat across a large portion of it. Placing a thin metal ruler down on the stone and then placing the iron so that the ruler slightly elevates the end effectively reduces the amount of work required to get a flat surface on the back.

Putting a back bevel on a bevel down plane increases the effective cutting angle of the plane which can help with difficult woods, so that can be viewed as an added benefit of the "ruler trick." But like nearly everything else it's a trade-off.

[Frank Drew]

Pam, Don, thanks.

[Mark Roderick]

I have a question about all this. I thought the reason for NOT putting a back bevel on a chisel is that you can't pare to a line, with the edge a tiny bit distanced from the back of the blade. Is this not correct?

[Mike Henderson]

I don't think anyone is advocating putting a back bevel on chisels. They were just discussing the "ruler trick" to put a back bevel, but it's mostly used on plane blades and not chisels.

Mike

[Don C Peterson]

Mark,

You are correct, I don't know anybody who recommends putting a back bevel on a chisel. The "ruler trick" is for plane irons not chisels.

[John Coloccia]

I just finished reading this thread, and the only thing I can think of is "Huh?". There's nothing wrong with a micro bevel on Japanese chisel. If anything, I would say that a micro bevel might even be preferred if you believe that it gives a bit more support to an already brittle edge (which was meant to work in soft wood) when working in western hardwoods.

There's a tradeoff in that Japanese chisels tend to have a primary bevel ground to 30 or 35 degrees to begin with. A micro bevel will increase this to 35 or 40 degrees, or thereabouts. Maybe that's not what you want, but there's nothing detrimental or "wrong". It's just something to be aware of.

I was in the same place a while ago when I got my first Japanese chisel. Everyone told me the moon would explode if I dared put a micro-bevel on a Japanese chisel. I finally decided that it was my money, my chisel, and I can do what I want, and it works just like it should, just like it does on any other chisel or plane iron. In retrospect, this should have been obvious but it wasn't. As it turns out, I decided I don't like a micro-bevel as I prefer the shallower cutting angle, and maybe this is why the micro-bevel is discouraged.

[Pam Niedermayer]

I have a question about all this. I thought the reason for NOT putting a back bevel on a chisel is that you can't pare to a line, with the edge a tiny bit distanced from the back of the blade. Is this not correct?

That's certainly one of my reasons.

Pam

[Frank Drew]

FWIW, I pretty much only worked in hardwoods and never had a problem with the edges crumbling or otherwise failing on my Japanese chisels; the idea that these tools are perhaps too fragile for Western hardwoods is incorrect, in my experience (with good tools, of course.)

[Pam Niedermayer]

FWIW, I pretty much only worked in hardwoods and never had a problem with the edges crumbling or otherwise failing on my Japanese chisels; the idea that these tools are perhaps too fragile for Western hardwoods is incorrect, in my experience (with good tools, of course.)

I work in hard and soft woods and also never had a problem with my Japanese chisels or plane irons, nor with western edges for that matter, except for one Funahiro that had a bad temper and broke about 3/4" up from the edge, replaced at no cost to me.

Pam

[Stephen Edwards]

Many arguments pro and con. Pam is correct in that it is typically considered a "no no" to put a secondary bevel on a Japanese chisel. But if you look at Krenov's books, you can see many examples of, not just a "micro bevel", but a noticeable "secondary" bevel ground into all of his Japanese chisels. (He would hollow grind his Japanese chisels too.) Toshio Odate recommends doing much the same thing on a much smaller scale by using a curving stroke on the last few passes over a polishing stone, lifting the handle while drawing the blade across the stone. Personally I never do either, preferring a perfectly flat bevel. One way or another, if you can shave with the blade, it doesn't get any better than that...

As I was reading this thread I was already thinking about Krenov's chisels when I got to your post, David. Well said.

Personally, I think what's important is for one to find what works for them, that they're happy with, and then carry on.

Though I've never seen any of Krenov's pieces in person, if the many photos of his work as shown in his books, and elsewhere, are a true reflection of the quality of his work, and I believe that they are, then the whole question of single bevel or double bevel being "right or wrong" is a moot point.

Again, whatever trips your trigger and works for YOU is all that matters, IMHO.