Japanese chisel out of flat?

[Tony Shea]

I just received a Nishiki chisel from TFWW. I was fairly dissapointed by the shape the back of the chisel is in, has a pretty good belly along its' length. Tried lapping it flat for a bit a checked agian with a straight edge. Made some decent progress due to the hollow but the tip of the chisel, say the last 3/16" is still out of plane from the rest. It is white steel. The rest of the chisel is great. I think in order to bring the tip in the same plane as the rest of the back I will need to almost remove the hollow. How normal is this for japanese chisels and should I not be trying to get the very tip it the same plane as most of the back? I'd think I'd want at least an inch of the back all in the same plane starting at the tip. But I'm new to these. My cheaper Iyoroi is flat across the whole back, odviously minus the hollow.

[David Weaver]

That is actually common. I've had chisels that were done both ways. One set of multi-hollow chisels that were definitely that way, and I have a couple of others that are, also.

by making it that way, the maker of that chisel intends for you to lap only the last half inch or so of the edge. The entire back won't be coplanar. It's assumed that you will get the first half inch or so of the chisel into the cut and that will be your bearing surface - a different philosophy than a dead flat american paring chisel.

Don't run the whole hollow out, you'll hate yourself later and marginalize the chisel, especially in terms of value. Just work the last half inch or so to the edge until you get to the edge itself and raise a wire edge.

my matsumura parers, iyoroi bench chisels and koyama parers are (iirc) flat on the back, but the chisels that I had that weren't were definitely not low quality reform school chisels. Since the back itself is hollow and since you're unlikely to be paring way in on a surface somewhere like a patternmaker might, you won't need more bearing surface than just what you get at the edge as I described. Trust your eyes and hands when you use the chisel, it'll work fine.

[Frank Drew]

Minus the hollow, my chisels are flat pretty much right up to the tang; any belly makes chopping straight very difficult.

Personally, I would have sent the tool back, although that might be a problem now that you've lapped it.

[David Weaver]

I think the nishikis that TFWW has are parers.

I know joel reads all of these forums, and sooner or later we'll hear whether or not they are intended to be that way. My guess is the blacksmith see is as appropriate, just because I've seen several like that before - new chisels that were definitely not bent in use, but having not seen these, who knows..

I would much rather have a chisel that's a little convex than one that's concave (i have seen a cheaper price bench chisel that was made concave, so much so that you can't actually get the blade flat because the socket is too far below the highest point in the middle of the bottom. It cannot effectively be used for a cut deeper than what I could get flat, which was about 3/4".

I use it bevel down to flush metal and hardwoods in an infill plane, which just kills the edge of a chisel when you accidentally contact an O1 side or something. Great use for that chisel, though, because it's hard and if it gets dingled up, no guilt in running out the nicks on the tormek and setting it up for another round of abuse.

[jamie shard]

I am half-way through tuning two Nishiki paring chisels from TFWW right now (haven't touched the bevel side yet). For what it's worth, both of my chisels needed lapping. When I ran them across a 800 grit stone, the scratches were about 3/16" from the end -- but the tip was definitely not 3/16" out of plane, if you mean that there is a 3/16" gap if you lay the chisel on a flat surface!

The lapping took some time, but by the time the scratches move up to the tip you really couldn't notice a loss of metal, there is still a significant hollow on the bottom of the chisel.

I already like these chisels and they're not even fully sharp yet!

[Tony Shea]

No, they are def not 3/16" out of plane. I was just stating that the last 3/16" or so is out of plane with the rest of the back after spending some time lapping. But I've decided to just carry on with my lapping and consentrate it on the last 3/4" or a bit more. I've got it close last night but still need a bit more. Just didn't expect them to come so out of flat, especially as this is the most expensive chisel I have to date. Am waiting for some 3M stikit paper in the mail to finish it out. I really like the feel of this chisel so decided it is worth my effort in getting it flat opposed to sending it back. But the hollow def has been decreased in the proccess but think I'll still have plenty left.

[Tony Shea]

Oh, and these are not parers. They are Umeki-Oire-Nomi dovetail chisels. I certainly would not want a paring chisel with a belly. Joel did respond to me and said that Nishiki can be inconsistant at times but he believes the chisel is intended to be this way as they only expect you to lap the front part flat. Which in my chisel's case was not possible until I got through a bit of metal just behind the tip. But all is well and will get back to seeing how it holds up.

[David Weaver]

Yes, the bench chisels that I had, i had to do the same thing - go through a fair bit of metal at the chisel edge.

The koyamaichi DT chisels are dead straight.

However, of all of the chisels where it wouldn't make a difference, dovetail chisels are at the top of the pack, and I wouldn't care less if they were convex like that. I used the bench chisels I had without consequence anywhere that I noticed. I ended up selling them to a buddy when I got more bench chisels down the road, and he hasn't complained yet.