Chisel "lands" (sides) ?

[Mike Holbrook]

I think the term land in the context of chisels refers to the various ways the sides/edges are made? I thought I would make a post on this subject as it has been mentioned in several other posts but the actual definition was never qualified. The buzz around this term seems to revolve around how the sides of the chisel will work in corners and against the sides of dovetails.

It would seem obvious that trying to shove a square box into the more acute angle of a dovetail side would "bruise" the side's wall. I think this is why chisels come with quite a variety of land designs. The Japanese Shinogi chisel design, for instance, slopes both of the chisels sides to a single point at the top of the chisel, while the Kaku-uchi's sides are much closer to 90 degrees. The subject is somewhat more complicated than the single angle though as the bottom corners of chisels with sloped lands are sometimes rounded, chamfered, or the corner is ground off leaving a 90 degree edge.

The western world seems much more interested in dovetails than our friends in the eastern regions. I think all this talk about lands centers around having chisels with lands that can reach into the acute angles in dovetail sides without "bruising" the sides? Another question regarding lands has occurred to me though. The little experience I have with chisels suggests that the bottom corners of most chisels are the most fragile part. It seems to me, these corners would be more fragile than the rest of the cutting edge if the bottom corners are not 90 degrees. An angle of less than 90 degrees essentially creates more of a point, which would be easier to break off.

I would think, the bottom edge of a Japanese chisel would be even more susceptible to corner breakage due to the harder (more brittle) steel typically laminated to the bottom edge. As I understand the design of Japanese chisels the softer steel, used for the majority of the chisel body, serves as a shock absorber for the harder steel on the cutting edge. Therefore it would seem that a more acute bottom edge on a Japanese chisel would leave the harder steel exposed without softer steel above it to absorb shock.

I raise this question because it occurs to me that in our enthusiasm for chisels with acute bottom edges might we also be subjecting ourselves to chisels with inherently weak steel at the most fragile part of our chisels? Might Japanese chisel makers have a reason for making lands the way they typically do?

[george wilson]

The old timers who just had firmer chisels would simply grind an angle at the leading square edge of their chisels. It was a steeply tapered bevel,which tapered out at about 1/2" long. This gave enough clearance right at the cutting edge end to clean out dovetails. A rather ugly,but functional modification to a firmer chisel to make it suitable for dovetails.

[Derek Cohen]

Hi Mike

To be clear, it is the tails that require a chisel with shaped sides and fine lands, and very narrow tails at that. Pins have walls that are square and one may use any chisel to clean out their waste.

Some will argue that sharp lands are unnecessary for chiseling in most tails. This is true to some extent. With wide tails one may simply use a narrower chisel, one that allows the chisel to be skewed into the side walls. This is not always convenient, but it is possible. When tails become too narrow to perform this strategy, then there is no option but to use a chisel with narrow lands. Further, it is always preferable to make a single chisel cut at the baseline, and then one is looking for a chisel that fits well. It would also need to have fine lands to fit without bruising the sidewalls.

I like slim dovetails on the drawers I build. They just look more elegant to me. Here I am referring to baselines that are 1/8" - 1/4" wide and tapering to a point. I use chisels to fit (1/8", 3/16", and 1/4"). Carcases receive wider dovetails. Even so, it is convenient to have the right tool for the job - one can get away with improvising, but why bother - chisels are one of the cheapest tools around.






Regards from Perth

Derek

[David Weaver]

I've been using the koyamaichi dovetail chisels that LV and Stu sell (you have to ask Stu, he can't list them) for about 6 years, and have used them for dovetails in everything from pine to oak/maple, no problem with the corners. Very hard steel can be brittle, but it's susceptible to twisting or levering forces, which you won't apply to them.

You don't need chisels like that, like derek says, but you can do your dovetails half asleep and still not bruise anything.

I think the reason they probably don't show up much in traditional japanese chisels isn't an issue of strength, but more an issue that they don't expose dovetails, etc.

[Ed Looney]

With the modern metals we have today breaking off a corner could happen but I think in most cases it would be a situation of where the operator had the philosophy of why sharpen when I can just hit it harder. Sharp tools require less pressure to make them cut and it is easier to control a tool with less pressure applied. If enough pressure is being applied to fracture a corner then I would question safe operation. I am not making a blanket statement for every situation because I know stuff happens. However there is a line that if crossed moves the chisel out of safe operation when to much pressure is applied. If I fractured off a corner then I would have to wonder if I crossed that line. I would have plenty of time to ponder is there a better way while I was grinding and honing a new edge.

Ed

[Sean Hughto]

http://www.flickr.com/photos/8842466...0862/lightbox/

[Stuart Tierney]

IMGP7685 (Custom).jpg

Look very closely at the chisel on the right...


Folks over here don't make many dovetails as folks in the rest of the world do (they're usually completely concealed here, and can be as messy as you want), and nobody from outside of Japan has ever really asked anyone inside Japan for a proper chisel for the job.

Nobody asks, they don't make them.

My concern is that over here in Japan, if you design something you do not really have a 'lock' on it, and someone, somewhere will copy it unless you take extra-ordinary measures or carry a really big 'stick' and now that I've posted that picture, it's only a matter of time before that shape turns up somewhere else.

Oh well. Getting used to that kinda stuff now, but still doesn't make it any nicer to deal with...

Stu.

(Dave, Koyamaichi shinogi will be listed properly, on their own soon enough. That 'deference' agreement got thrown out the window a little while back. You know why. )

[Mike Holbrook]

My point is a more acute angle, in my opinion, has to make a more fragile front corner. I think I am hearing David, Derek and Stuart saying, the angles in question are not so great as to cause problems large enough to outweigh the benefit of greater ability to reach into corners. I believe David and Derek both have Koyamaichi Shinogi chisels which have steeper beveled sides and sharper bottom edges than anything I have or would think about purchasing. If they have not had problems with the edges on their chisels I imagine any risk is minimal.

Nice looking chisels Stuart! I think you feel the more acute angle on the side/land on the chisel on the right is a better design for dovetailing than what I imagine is a standard Kaku-uchi pattern on the left. Assuming these are both orie-nomi patterns, it would seem that this pattern might have a number of advantages as compared to more conventional bevel edged patterns.

[Sean Hughto]

I've broken a bench chisel only once; many years ago when I was just starting to chop my own mortises, I pounded a regular half inch 750 into some maple to the point it got stuck. When I tried to pry it back and forth to loosen it, the leverage action snapped the chisel. It was a ham handed rookie error. Since then I've never even had a chunk of bevel break off. In short, in normal use, your strength concern is not an issue.

Carving gouges on the other hand can be quite delicate, and I often lose chunks of edge in hard woods.

[Stuart Tierney]

Nice looking chisels Stuart! I think you feel the more acute angle on the side/land on the chisel on the right is a better design for dovetailing than what I imagine is a standard Kaku-uchi pattern on the left. Assuming these are both orie-nomi patterns, it would seem that this pattern might have a number of advantages as compared to more conventional bevel edged patterns.

Mike,

That shape came along after a few false starts and a little skull sweat.

The original chisels, made late last year, were a 'zero land' Shinogi and that design, while ideal on the face of it (sharp corners, no risk of bruising the corners, maximum angular clearance) it's a great idea, in reality it doesn't work.

But you don't find that out until you actually use said chisel and discover how dumb it really is, even though it looks cool.

Sharp, acute corners are dangerous. They'll cut you. They also tend to 'stick' into the wood if there's no wiggle room, and if there is wiggle room, they may bite in and stick.

Acute corners are also troublesome to make, especially by hand. The slightest over grind, and you get a tapered chisel that'll wedge tight into the workpiece if there's no side clearance, which a chisel by it's very nature is likely to do.

And that chisel, it's not just the side angle relative to the back that's been tweaked...

As far as strength and durability goes, these things will be fine.

Stu.

[Jack Curtis]

That shape came along after a few false starts and a little skull sweat.

The original chisels, made late last year, were a 'zero land' Shinogi and that design, while ideal on the face of it (sharp corners, no risk of bruising the corners, maximum angular clearance) it's a great idea, in reality it doesn't work. ...

Stu, what do you think of the Tasai dovetail chisels type 1?

PS I think your chisel looks a bit thick for anything but chopping. Have I misperceived?

[Stuart Tierney]

Stu, what do you think of the Tasai dovetail chisels type 1?

PS I think your chisel looks a bit thick for anything but chopping. Have I misperceived?

That's a fishtail chisel, the ones I put up are not. Fishtail for pins, the ones I put up for tails.

The plan is that the chisel I posted is use to chop out the waste between tails, be strong enough to do that job without fear of harming it, and for it have enough of a side angle to fit into most joints (sides are 75° to back) and no 'flat' down the sides. By sheer co-incidence, they're also quite good as a general purpose chisel. Maybe not ideal for excavating mortises with their more angled sides, but for most chiseling work, pretty good.

(Best 'all purpose' chisel I've ever used to be honest.)

To a point, while I know that I can pound a good shinogi-nomi into a piece of hardwood and never have a problem, the slimness of the tool tweaks my sense of mechanical sympathy. These things, no such fear. They have more meat on them than a mentori-oire, and I don't have many reservations smacking one of them into hardwood.

(Unless it's a cheap chisel. And even then, a good one will let you get away with it. If you're lucky!)

Fishtail, paring out between pins on a half blind joint. Tasai are nice, they're good people but I wish they didn't cost so danged much. But if they cost less, they wouldn't be what they are. Never seen anything but near perfection from Tasai.

One thing I would ask them to do is make the neck and socket match up smoothly. Never liked those sharp edges where the neck and socket meet like that.

(There are matching fishtails for the chisels I posted up. My only reservation about the matching fishtail is that it's got a hollow in it's back I don't think it needs, but the fellow who made it thinks it needs to hollow to be 'complete'. We'll argue that point, and it still doesn't make any difference in how the thing works.)

IMGP7700 (Custom).jpg

Completely different animals. Yes, perhaps a little mis-perception.

Stu.

[Tony Shea]

I have personally had the problem mike is questioning with a lower end Japanese dovetail style chisel and also a western fishtail chisel. On both chisels I have a small little break on the very corner of the bevels edge. I am probably to blame for both failures though. One should recognize that these chisels are potentially fragile on this area and and twisting or prying with these chisels should not happen even if the waste in a half blind pin socket is being really stubborn (fishtail chisel incident).

[Mike Holbrook]

Tony thanks for letting me know that I am not completely addle brained yet. The chisel I just bought on "an auction site" is a Tataki (Atsu?), heavy striking, type with a blade made like a mortise chisel but with a standard round throat. I am working on restoring the cutting edge as one corner was missing a fair chunk and the other was not great either. The chisel may have been dropped or abused in some other way, still that is the only issue on a 15mm heavy duty chisel that is some 30 years old.

I have been studying Frank Klausz's methods for making dovetails. Frank's methods tend to make larger pins and tails. Frank thinks larger dovetails are the strongest. I admire Derek's work above, but it seems to me to start falling more into a wood art category which I presently feel ill prepared to tackle. The projects I have now are oriented more towards heavy use and abuse cabinets and work surfaces. I think "bench" chisels like the ones Stuart shows us above will serve my present work better. I plan to try a Chu-tataki-nomi (a little heavier than oire-nomi), a Usu-nomi (paring) chisel, and a couple mortise chisels too, maybe then I will have a better feel for the wider variety of Japanese chisels and their various lands.

[David Weaver]

I dropped three of the koyamaichi dovetail chisels at the same time about 5 years ago. Each of them hit the concrete floor blade first and bounced around. They all had their corners chipped off and nothing else, so I'd suspect that dropping was the reason for that corner on yours, too, Mike.