Uraoshi Sharpening - Blade side

[shauk]

Hey KKFer's,

I came across the sharpening section from Sakai Takayuki's Japanese catalog (堺孝行刃物 総合カタログ FULL PRODUCT LINEUP VOL.6) and wanted to check if this guide is asking the users to finish the Uraoshi at a slight angle (few passes) for some strength.

Is this correct?

 

[D J]

I've never sharpened owned or used a single bevel. From what I've seen, I thought the flat side was meant to stay flat. Will be interesting to see what those more experienced will say.

 

[ethompson]

I'd much prefer to add more convexity to the kireha or add a small micro-bevel on the other side than do this. Once you cut in that bevel on the back sharpening and long term maintenance is going to get a LOT more painful

 

[noj]

Interesting. I bought one of their knives (new) a while back, and found a bevel on the urasuki side, and wondered what that was about. I removed it, while fixing a large number of "defects".

 

[Dan-]

At most I put a small bevel at the heel on urasuki, and that’s only for debas. I might do something similar for a garasuki, but I haven’t yet sharpened my SK garasuki (though it needs it).

 

[shauk]

I am guess this is like a ultra micro bevel, I cant read Japanese but is probably saying 1/2 passes on a high grit stone for this?

Possibly width of 0.7mm ?

 

[cotedupy]

I'd much prefer to add more convexity to the kireha or add a small micro-bevel on the other side than do this. Once you cut in that bevel on the back sharpening and long term maintenance is going to get a LOT more painful

^ What ET said ^

Microbevel on the omote - fine, and can be useful for deburring. Microbevel on the ura - not fine, and will annoy the f out of you later.

The uraoshi is also the easiest thing in the world to make flat / have contact with the stone, once. Even if it didn’t screw over your future self, I still can’t see any reason you’d want or need to microbevel it...(?)

 

[cotedupy]

I sharpened a Global yanagiba today (who knew?!), which was a *quite considerable* challenge, to say the least.

But I still didn’t have to microbevel the ura.

 

[ethompson]

Having taken out a bevel from the backside of a couple used single bevels so that they're able to be maintained easily again is enough to tell me this is a terrible idea. Even a couple passes on anything less than a 10k+ stone would make me anxious honestly

 

[cotedupy]

Reading your OP back again, and actually this is interesting:

for some strength.

Now that's not something you really need in a properly sharpened yanagi... but it might be in a deba.

(I have literally never used a deba for filleting fish, so can't comment there I'm afraid. But I most certainly wouldn't do it on slicers - far more trouble than it's worth).

 

[EShin]

Hey KKFer's,

I came across the sharpening section from Sakai Takayuki's Japanese catalog (堺孝行刃物 総合カタログ FULL PRODUCT LINEUP VOL.6) and wanted to check if this guide is asking the users to finish the Uraoshi at a slight angle (few passes) for some strength.

Is this correct?




View attachment 247546

The pictures are odd as they seem to suggest that you should do the uraoshi sharpening at a slight angle but the text is actually saying that the ura needs slight sharpening but a micro bevel or some convexity should be added to the front of the blade and not the back (ura) - so just as cotedupy and ethompson above suggested. That will give you enough strength for your yanagiba or usuba, which the explanation is about. Adding a micro bevel to your ura is a very bad idea.

 

[natto]

A and B points out bevel width on the ura. Below picture shows an ura without bevel. Touching the ura with last deburring only might do this. Looks like a don't do this picture. Without sharpening the ura the edge will fail.

they seem to suggest that you should do the uraoshi sharpening at a slight angle

Can that be read as sharpening the ura a little more, or at least enough? At least this would get the "don't do this" edge stable.

 

[EShin]

A and B points out bevel width on the ura. Below picture shows an ura without bevel. Touching the ura with last deburring only might do this. Looks like a don't do this picture. Without sharpening the ura the edge will frail.


Can that be read as sharpening the ura a little more, or at least enough? At least this would get the "don't do this" edge stable.

Yes exactly, it says that the ura requires sharpening/flattening because the edge would be too weak. The picture on the right explains that you should however not make the whole ura flat. Still, I think the explanations are not very helpful as it’s too easy to mess up the ura if you don’t mention that only very fine grits should be used, but say that the ura needs around 1 stroke for every 10 strokes on the front.

 

[simona]

Have a look - there are plenty of single bevels being sharpened here - he always shows the final finishing on stones, if you don't want to watch from the beginning.

https://www.youtube.com/@hatsukeya

 

[noj]

Yes exactly, it says that the ura requires sharpening/flattening because the edge would be too weak. The picture on the right explains that you should however not make the ura flat. Still, I think the explanations are not very helpful as it’s too easy to mess up the ura if you don’t mention that only very fine grits should be used, but say that the ura needs around 1 stroke for every 10 strokes on the front.

Interesting, every video I have seen shows the ura placed flat on the stone, which would seem to make it flat. I can't see enough detail in the link above to tell - though I did not watch all of them.

 

[noj]

Interesting. I bought one of their knives (new) a while back, and found a bevel on the urasuki side, and wondered what that was about. I removed it, while fixing a large number of "defects".

In case this was not clear, it had a flat (or nearly so) ground ura, and on top of that a big fat not very micro bevel on both sides. I was not happy.

 

[EShin]

Interesting, every video I have seen shows the ura placed flat on the stone, which would seem to make it flat. I can't see enough detail in the link above to tell - though I did not watch all of them.

Sorry, my language wasn’t clear. Of course you’re right! What is written is that while you should flatten your ura, you shouldn’t flatten the whole but just flatten around 0.7 mm at the edge.

 

[noj]

Sorry, my language wasn’t clear. Of course you’re right! What is written is that while you should flatten your ura, you shouldn’t flatten the whole but just flatten around 0.7 mm at the edge.

Oh! For sure, that would be bad;-)

 

[shauk]

Yeah will stick to sharpening on a high grist stone and flat for the Ura side.