Japanese Chisels

[David C]

My sharpening time for Japanese chisels is exactly the same as for my European chisels!

I have no use for the single polished bevel.

It is clear that Japanese chisels are better when one works dense exotic timbers.

best wishes,
David

 

[D_W]

My sharpening time for Japanese chisels is exactly the same as for my European chisels!

I have no use for the single polished bevel.

It is clear that Japanese chisels are better when one works dense exotic timbers.

best wishes,
David

Mine differs because it's only about 30 seconds for a western chisel, and enough time needs to be spent on japanese chisels at some point to grind the bevel.

However, I've found that japanese chisels that are a touch soft will sharpen fantastically on a single washita stone. It can't cut them deeply, so they are still blindingly sharp. I also deal natural stones (mostly japanese), so I've got just about everything on hand, but really like the washita - very practical and something pretty horrid has to happen to a japanese chisel for it to be too slow. It also preserves the visually rewarding single bevel as well as the look of a natural stone with stark contrast.

I do use the japanese chisels when making plane mortises in beech. A mortise, 15 seconds on a washita, another mortise, 15 seconds on a washita. It's a really nice circle. I don't have many western chisels that are as stout and short, or I'd probably use them, too. (there is a conflict in my statement here about time, but mortising a plane is a different thing -it is an exercise in abuse, and chasing the finest edge and trying to keep it is not productive - a quick touch up to correct an edge is just fine. Smaller and finer joinery, that's not really the case, and the penalty is large if you chip the corner of the hardest chisels, like the older ouchis).

What I've found over the years for exotics (again from plane making, mortising cocobolo or something particularly hard on the flat sawn face) is that most western chisels will give up at the standard angles, but an additional two or three degrees is all that's needed. At some point (angle steepness) in the exotics, chips fly instead of peeling, and some may find that a bit undesirable. I kind of like it in a plane mortise as those chips exit the mortise with no assistance, but it some of the chips can end up 20 feet away in a corner.

Not debating that japanese chisels are wonderful - I love them all (western and japanese) unless they're improperly hardened or errantly made (i have broken a japanese mortise chisel that wasn't properly welded, and only in routine mortising of cherry). They can be a bit of an indulgence, and I've gone so far as to pick up three kiyotada chisels (two used). At the price most others are brought to us in the US new, I'm out. Too many links in the chain adding price, and thankfully some based in japan have noticed that and begun offering sets for reasonable prices direct shipped, but the makers are protective of their distribution networks, and there are a few over there looking to get "a little extra from gaijin", like a dealer who charges an additional 40% if you read their site in English instead of japanese (based on a plane I once bought for $350, but like other things, was $500 on the site in English). Anyway, not particularly relevant.

 

[ED65]

But like I said before I always maintain a slightly convex bevel for extra mechanical strength.

I'm extremely doubtful that a convex bevel is materially stronger than a flat bevel. Assuming the same angle at the edge and a modest curve to the bevel.

Looked at theoretically it is easily seen how flat or convex is stronger than concave but even there edge failures are uncommon, as in: practically unheard of. With flat v. convex though, near the edge there's virtually no difference in fact and further back from this the shape of the steel is irrelevant (as regards directly contributing to strength at the edge)

 

[ED65]

They are much harder than anything from the West. Usually between 62 to 64 Rockwell C scale. Most European chisels are around Rockwell 58, which is significantly softer, as the scale is not linear.

I know for someone like yourself this may not be something you'd care to do or have time to experiment with but a Western chisel can be re-hardened quite easily, with minimal kit, and then tempered to any degree desired. Or not at all if you want to see if it's usable at peak hardness or just too brittle to be practical.

Any chisel found to be too brittle can be re-tempered without starting the process from the beginning, so it's not too onerous to find the steel is crumbly and needs to be made a smidge softer for another try.

My sharpening time for Japanese chisels is exactly the same as for my European chisels!

Is this due to using a secondary or tertiary bevel?

And if I may ask, what is your normal re-honing time?

 

[D_W]

But like I said before I always maintain a slightly convex bevel for extra mechanical strength.

I'm extremely doubtful that a convex bevel is materially stronger than a flat bevel. Assuming the same angle at the edge and a modest curve to the bevel.

Looked at theoretically it is easily seen how flat or convex is stronger than concave but even there edge failures are uncommon, as in: practically unheard of. With flat v. convex though, near the edge there's virtually no difference in fact and further back from this the shape of the steel is irrelevant (as regards directly contributing to strength at the edge)

The abuse failures you get in japanese chisels are things like corners disappearing, etc, at acute angles. You have a choice to either make the angle steep (you'll find people who put a 35 degree bevel on a japanese chisel with some regularity, and that's pretty harsh if you're trying to get the chisel through something).

It's not that the convex bevel is stronger in this case, it's that the tiny convex bevel is added just to the very edge of the chisel to strengthen it and avoid the chipping failures that are common when you get a little too rough. (so it's not the same angle as a single bevel would've been) You can do the same thing with a western chisel if you get in some rough going. The reason it's enticing on japanese chisels is because the hardness makes their wear really slow if you can eliminate most of the chipping.

David C has several videos that do the same thing faceting microbevels rather than making a small convex bevel. The speed of the small convex touch up with a slow stone is undeniable, and the time that it saves in averting failures in hardwoods is just as worthwhile as it is microbeveling as David C does. The draw of the slow stone in making a rounded bevel is that you can make the bevel very small and eliminate it quickly with some medium stone bevel work if you want it gone (e.g., if you go back to working in softwoods after a piece that's much harder).

I have talked to several professional users of japanese tools who advocate the same thing, both for bevel strength, and for insurance that the finish stone actually addresses the edge without a bunch of additional work.

 

[Saer Llongau]

They can be a bit of an indulgence, and I've gone so far as to pick up three kiyotada chisels (two used). At the price most others are brought to us in the US new, I'm out. Too many links in the chain adding price, and thankfully some based in japan have noticed that and begun offering sets for reasonable prices direct shipped, but the makers are protective of their distribution networks, and there are a few over there looking to get "a little extra from gaijin", like a dealer who charges an additional 40% if you read their site in English instead of japanese (based on a plane I once bought for $350, but like other things, was $500 on the site in English). Anyway, not particularly relevant.

I bought my chisels directly form the factory through my cousin. The owner didn't want to do it at first because he didn't want to upset his distributors. My cousin gave him a message from me about how sad I was because his chisels weren't available in Europe (which was true). After a bit of convincing by my cousin he reluctantly agreed to sell them to me directly and that saved me quite a bit of money. Little did he know I was in Japan 2 months later :lol:

I'm extremely doubtful that a convex bevel is materially stronger than a flat bevel. Assuming the same angle at the edge and a modest curve to the bevel.

You can doubt it all you want but it doesn't change the fact that more material behind the edge=stronger edge. Any decent chisel blacksmith will tell you the same thing. My own experience in hard, dense, White Oak confirms this as well.

David C has several videos that do the same thing faceting microbevels rather than making a small convex bevel. The speed of the small convex touch up with a slow stone is undeniable, and the time that it saves in averting failures in hardwoods is just as worthwhile as it is microbeveling as David C does. The draw of the slow stone in making a rounded bevel is that you can make the bevel very small and eliminate it quickly with some medium stone bevel work if you want it gone (e.g., if you go back to working in softwoods after a piece that's much harder).

I have talked to several professional users of japanese tools who advocate the same thing, both for bevel strength, and for insurance that the finish stone actually addresses the edge without a bunch of additional work.

That's exactly how I do it, with a slower stone (a medium fine Aizu)

 

[D_W]

That's exactly how I do it, with a slower stone (a medium fine Aizu)

It's not by chance that we both came to the same method and the same preference. It just works ideally and all of the talk about fragile edges goes away. Still slips through wood very well requires very little maintenance. I've adopted the same thing for my western chisels now. The primary bevel is who knows what, and the secondary bevel is a tiny rounded bevel done by a very slow and shallow cutting fine stone.

As far as the distributors not going against the rules, my favorite saying over there is "the nail that sticks out will be hammered down". If they have an agreement with the agent and the agent is Japanese, it's serious business keeping your word.

 

[Saer Llongau]

The primary bevel is who knows what, and the secondary bevel is a tiny rounded bevel done by a very slow and shallow cutting fine stone.

I have the main part of the bevel at something like 28 degrees and the rounded end part of the bevel is about 32 degrees. That gives me a chisel that's easy to chop with and a very tough edge.

 

[ED65]

I'm extremely doubtful that a convex bevel is materially stronger than a flat bevel. Assuming the same angle at the edge and a modest curve to the bevel.

You can doubt it all you want but it doesn't change the fact that more material behind the edge=stronger edge. Any decent chisel blacksmith will tell you the same thing. My own experience in hard, dense, White Oak confirms this as well.

Sorry I didn't express the source of my doubt clearly enough. It's not having more material behind the edge being stronger, it's whether there is. The following images should make it clear what I mean.

At and near the edge there's no difference at all between A and B. Clearly C has a source of weakness, although often not significant in homogeneous steel.

I've tried to be fair in showing the genuine shape of the convex and concave bevels but these were drawn without references so apologies if the the geometry isn't quite right.

 

[Saer Llongau]

We can debate it until the end of time but the only thing that will convince you is to actually use a convex bevel yourself.

Edit: To stay with things Japanese, this arrived today. A Maruoyama Shiro Suita, the ultimate Suita. On the hard side of medium hardness and muddy. This is without a doubt the most pleasurable stone I've ever used.

 

[ED65]

All my chisels have convex bevels and have done for the last few years. It's just that they're a completely different profile (as in the diagram) which is what I thought you were talking about from the initial reference.

 

[Saer Llongau]

My bevel is a normal flat bevel with a secondary convex bevel. I round over only the tip of the bevel so in that respect it's much like a secondary bevel. The difference is that by rounding it over I create more material behind the edge.

 

[D_W]

All my chisels have convex bevels and have done for the last few years. It's just that they're a completely different profile (as in the diagram) which is what I thought you were talking about from the initial reference.

It's the extra four degrees and not the shape. The convex bevel requires no additional devices, though, and for going through wood, the shape is more refined than a flat bevel. The cut has to be heavy before the refinement matters.

 

[Saer Llongau]

The convex bevel requires no additional devices

That's exactly it. When you've done it enough times muscle memory kicks in and it becomes part of the normal sharpening routine.

 

[Derek Cohen (Perth Oz)]

Just to stir things up a little ....

I've used these cheapish Iyoroi chisels for about 20 years. They are hollow ground on a Tormek.

Never chipped an edge in the local hardwood.

Regards from Perth

Derek

 

[Beau]

Just to stir things up a little ....

I've used these cheapish Iyoroi chisels for about 20 years. They are hollow ground on a Tormek.

Never chipped an edge in the local hardwood.

Regards from Perth

Derek

This is the sort of quality chisel I was on about when starting this thread. Cant say I hollow grind as my grinder is flat but sure it works fine but I suspect reason they dont chip is they are touch softer than the exotic Japanese chisels that seems to be what many associate with Japanese chisels.

 

[D_W]

Just to stir things up a little ....

I've used these cheapish Iyoroi chisels for about 20 years. They are hollow ground on a Tormek.

Never chipped an edge in the local hardwood.

Regards from Perth

Derek

I asked stu about these once, because I have a version that is just mokume, but is probably otherwise little different. In the US, they're derided as chisels that aren't worthy of having. In Japan, apparently they have the same kind of reputation as we put on an old stanley plane. They just work, they're not flashy, and not derided for being what they are.

 

[AndyT]

They just work, they're not flashy, and not derided for being what they are.

That's a nice description, not just for tools, but for people to aspire to as well.
I could be quite happy with that!

 

[Beau]

[ They just work, they're not flashy,.

Exactly.

I prefer the balance and have found the edge better than the few European chisels I have tried.
Not knocking other chisels but felt that the Japanese seem to be derided on here for what I saw as unfair reasons hence starting the thread. Clearly the high end ones are another kettle of fish and one I will leave to others.

 

[D_W]

Here is what the mokume version looks like:

https://s2.postimg.org/ix7hozz5l/20170806_165207.jpg

(I don't think there's much difference between these and the budget ones, except for the wrought iron. They are nice to sharpen on natural stones because the wrought gives way easily to the stones.).

I remember getting these (they are available in general, but I wouldn't recommend them at regular price - I got them for half price or a little less), and someone chewed me out because "iyoroi's mokume isn't well done"

They're cheaper than LN's chisels (and better), who cares what the mokume looks like? I do like the softness, but would like it just as much if it was plain black. If one doesn't think the shape is refined, you can always grind them.