Tanaka blade not straight

Hey all, I bought a Tanaka Gyuto a little while back, but it appears there is something that has been nagging me about the blade, it appears there is some wobble in the neck and the blade. I know its a cheaper knife and I probably shouldn't be bothered by it, I can handle a crap handle but a non-straight blade irks me for some reason. Anyways, I think its off around a quarter inch or so at the tip. I tried to take a few pictures of the gyuto, what do you guys think? Am I just crazy?

I also have a 210mm Ginga, where I notice no issue with straightness just to add in my defense.

Whoops heres a link to pictures.

curves to the left, right? Not so hard to fix... where are you located?

JBroida said:

curves to the left, right? Not so hard to fix... where are you located?

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I think it curves slightly to the right then to the left if that makes sense, at least at the tip it curves to the left. I am located in Canada, I've been considering shipping to your Jon since Knife can't fix it and Tosho never got back to me so I don't think they are equipped either.

i would do it for free if you cover shipping, but i know that adds up... anyways, at least you have a backup option if the other things dont work out. I can also try to explain the process of fixing it and work with you via skype if you would prefer to give it a shot yourself.

Wow Jon, I have heard tales of your phenomenal service and they really are true. If you ever land some more kochi's in stock I know what my next knife will be. I'll weigh my options to see what will work best but thank you again!

A better way in my opinion to check if the blade is bent is to hold the knife spine down and point the tip towards your eye and check along the edge if bent.
this will tell very acurate if it's bent, also flip it spine up and check if the bend is located in the same area as the edge.

I usually take a look straightness pointing the handle to the eye also, both spine and along the edge

If bent it's fixable but if twisted... not so easy

You might also try to straighten it yourself. I've been in your situation once and was able to get the job done. It wasn't hard but it made me nervous...

To see the bent better you can put the knife against the flat surface face down and look against the spine. You will the gaps where light leaks.

Easy fix if it's just bent. Bend back into shape yourself

havox07 said:

Whoops heres a link to pictures.

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Hard to tell with those pictures without a straightedge for reference.

I'll post a few more pictures. From placing it on a table I can see it is mainly bent around where the kanji is found. I have tried to bend it back slightly there.

Just bend it back? I dropped my kono hd the other day on rubber mat and noticed it yesterday while sharpening that it was bent. I'm interested in finding out how to fix this as well...

Alright just to update I think I have pretty well fixed it with a little bit of bending back. Really was quite easy, just used my desk as a flat service and bent back the other way with my hands, surprising how easy it was to do with my hands. Although I guess that is due to the soft steel cladding, and the hard core steel not contributing much to preventing flex then?

step one: sight down the cutting edge of blade, do this with the edge parallel to the floor. watch your eyes/face...!
step two: place your finger on the face of the blade where you notice things start to go "pear shaped" as our friends across the pond say...
step three: place the blade on a flat surface, preferably one you know to be level. you want to be able to bend the knife in the opposite direction of the curvature.
step four: bend the knife back into shape using your hands and sight down the cutting edge in the manner described above after every attempt. Go slowly and gradually apply pressure. Holding the knife in the middle of a bend is going to give you more results than trying to apply lots of pressure and holding the position for a few seconds. OR get a big stack of books and put the entire blade on the flat surface, books on top. Come back in 12-24 hours and sight down the cutting edge.

for safety: cover the blade with a cloth while you are bending and be sure to orient your face away from the blade. you should know if you are bending too far, the blade will tell your hands when the steel is straining there is a noticeable tactile response. If anything starts to feel different, stop, sight and try again, applying less force. It's not hard. I would recommend the book method for thicker/stiff knives. Do the best you can, do not go overboard or you will likely end up with a more complex twist which CANNOT be fixed as easily.

You can also make jigs with 2x4 and a router, I believe KnifeWear has a video on youtube on how to do this? There are similar jigs for bending wire, I've seen at lee valley. This is probably a much more reliable method but the table/book method has granted me many a straightened knife over the years.

My understanding was that handmade things are not in perfect true anyway. I have read that about k sab carbone etc. western knives. I know for a fact some of my favourite knives have 0.1mm deviations from being perfectly straight. Have I ever noticed it while cutting? No. Because I am nearly incapable of producing even relatively consistent julienne, brunoise etc by hardcore ocd or kaiseki standards.

I don't think I've ever received a perfectly straight knife either. I don't have a t square or anything like that but that's just my impression from sighting down cutting edges all the time. I could return product all day long with a decent enough SLR camera and appropriate tools at my disposal. Then again I've not bought anything over 200USD yet.

One last thought: just because the spine of your knife isn't straight doesn't mean there's the same problem further down the knife (ie. cutting edge). Sight the blade like a blacksmith, ignore the spine and hold the edge parallel to the floor, sighting down that.

I thought I would update this, I got it straightened and rehandled at Tosho a few weeks ago. Then yesterday after doing some work to ease the choil I found it was again pretty far from straight. I had the blade in between a textbook so I don't see how that could have caused issues, does it just tend to bend back to its original state with time?

havox07 said:

I thought I would update this, I got it straightened and rehandled at Tosho a few weeks ago. Then yesterday after doing some work to ease the choil I found it was again pretty far from straight. I had the blade in between a textbook so I don't see how that could have caused issues, does it just tend to bend back to its original state with time?

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I think there's some type of "memory" that steel has... anyway I've had them return to original bent condition. Generally I take this to mean not enough force is being applied (you aren't bending far enough in the opposite direction). Might be time to send it to Jon?

I was in Toronto so I brought it back go tosho to see if they can fix it. Hopefully this will be the last servicing this knife needs. I think I understand the whole just pay the extra for better fit and finish blade, something like the Chiku would have cost around the same in the end with the rehandle and no headaches. :S