Yoshikane SKD folded edge

[Delat]

After using my new Yoshi SKD gyuto last night I noticed a good chunk of the edge was folded over. This is the original factory edge. I used it cut cut the bulb-end off individual garlic cloves (before peeling) and figure that must’ve caused the damage. Before I reach out to Epic Edge I wanted feedback on: 1) am I crazy for thinking this shouldn’t happen when cutting garlic, 2) why would HRC64 steel fold like this instead of chipping? I’ve heard that factory edges can be brittle and chippy, so does this fall under that bucket? Is this just user-error knife abuse of a thin edge?

This photo is taken with the knife flat, looking from the spine towards the edge that’s folded up.

This is the other side of the edge where you can see the gap from the folded-over section.

 

[ian]

Guess I’m a little surprised that it would have folded if it’s that hard, but I suppose it could if it was murderously thin bte. Does the edge flex if you press its side against your nail? I’ve definitely rolled an edge on garlic before, but that was a 59-60 HRC Ginga. Idk, tho

 

[captaincaed]

If it's just the very very edge that's rolled, I had a similar experience with both my SKD Yoshis. Those edges are so, so thin. It shows off what the makers can do, but isn't practical for most western cooking habits (board contact) in my view. They're some of my favorite knives if you get through this initial phase, but yeah, the OOTB edge isn't great for western customers.

If you sharpen through it with a mid grit stone at a slightly higher angle, you may be back in business.

If you've rolled more than just the very edge and have a warp in the edge (like, 1mm up or so, and the edge looks like it wanders if you look straight down the barrel of the knife from the tip to the handle), it may be worth taking more detailed pics and asking EE, or maybe reevaluate how much force you're using. (only an "if" statement here, not sure it applies in your case from the pics)

I rolled a very hard, fine Japanese edge into a fish hook before. It's definitely possible.
The title is my attempt at clickbait, sort of talking about a different topic. But, should let you know this can happen.

 

[Jason183]

Is it just me? Seems liked your cutting edge isn’t completely flat based on your 2nd picture. It looked slight hollow instead, if you try to lay it down on the cutting board and you see light through it, you should let the vendor know too, it’s not normal for new knife.

 

[Bensbites]

Is it just me? Seems liked your cutting edge isn’t completely flat based on your 2nd picture. It looked slight hollow instead, if you try to lay it down on the cutting board and you see light through it, you should let the vendor know too, it’s not normal for new knife.

Not just you… I was surprised, but then that edge wouldn’t contact the board. It must be an artifact of the camera right?

 

[captaincaed]

Draw a straight line across that picture - if that isn't spherical aberration from a lens, we have deeper issues

 

[Better call Leo]

Not just you… I was surprised, but then that edge wouldn’t contact the board. It must be an artifact of the camera right?

I also believe it is caused by camera. I have never seen that kind of shape for blade.

 

[Delat]

Is it just me? Seems liked your cutting edge isn’t completely flat based on your 2nd picture. It looked slight hollow instead, if you try to lay it down on the cutting board and you see light through it, you should let the vendor know too, it’s not normal for new knife.

Yes, I used a magnifying glass for the photo so the curve is just an artifact.

 

[Delat]

Thanks for the feedback guys, you helped calm my initial panic. Sounds like I should just clean it up and start peeling my garlic before trimming the ends, and see how it holds up. I really didn’t expect this steel to bend at all - none of my other knives have ever had an issue like this, but none are as thin and light either.

How would you recommend sharpening out the folded section? Should I try to straighten it first with an old-school steel, or just go at it with some edge-leading strokes on a coarse stone?

 

[Jason183]

Thanks for the feedback guys, you helped calm my initial panic. Sounds like I should just clean it up and start peeling my garlic before trimming the ends, and see how it holds up. I really didn’t expect this steel to bend at all - none of my other knives have ever had an issue like this, but none are as thin and light either.

How would you recommend sharpening out the folded section? Should I try to straighten it first with an old-school steel, or just go at it with some edge-leading strokes on a coarse stone?

I don’t see any serious sharpening for new knife, especially for Yoshikane( very thin BTE) I normally just did few passes on green compound strop and it’s back to razor sharp again, feel the edge with fingers until there’s no burrs/rolled edges.

 

[Checkpure]

Thanks for the feedback guys, you helped calm my initial panic. Sounds like I should just clean it up and start peeling my garlic before trimming the ends, and see how it holds up. I really didn’t expect this steel to bend at all - none of my other knives have ever had an issue like this, but none are as thin and light either.

How would you recommend sharpening out the folded section? Should I try to straighten it first with an old-school steel, or just go at it with some edge-leading strokes on a coarse stone?

Just put your garlic in a hard tupperware and shake the **** out of it till the skin comes off.

Don't worry too much about trimming the end and definitely use a knife thicker behind the edge if you want to roast some garlic and clip the bottom in the future.

 

[captaincaed]

I don’t see any serious sharpening for new knife, especially for Yoshikane( very thin BTE) I normally just did few passes on green compound strop and it’s back to razor sharp again, feel the edge with fingers until there’s no burrs.

How would you recommend sharpening out the folded section? Should I try to straighten it first with an old-school steel, or just go at it with some edge-leading strokes on a coarse stone?

From what I've seen, Yoshi are +3 standard deviations thin at the edge when new. They can be a little unusual.

The point is, you're not going to be able to straighten it out (mostly likely), the edge is pretty much fatigued. Yoshi edges are so thin, coarse is unnecessary, a little time with a medium stone should do the job. Sharpen just like you're sharpening.

If you try to strop, you'll damage the strop with a rolled edge. It's an edge pointing sideways/backwards. You don't want to drag that over your nice cotton/leather strop

 

[Delat]

The point is, you're not going to be able to straighten it out at this point, the edge is pretty much fatigued. Yoshi edges are so thin, coarse is unnecessary, a little time with a medium stone should do the job. Sharpen just like you're sharpening.

If you try to strop, you'll damage the strop with a rolled edge. It's an edge pointing sideways/backwards. You don't want to drag that over your nice cotton/leather strop

I figured the whole edge has to go, I was more concerned about gouging my stone with that section pointing straight down while sharpening. I’ll give it a go on my SG500 and hopefully it’ll abrade off quickly.

 

[Jason183]

From what I've seen, Yoshi are +3 standard deviations thin at the edge when new. They can be a little unusual.

The point is, you're not going to be able to straighten it out (mostly likely), the edge is pretty much fatigued. Yoshi edges are so thin, coarse is unnecessary, a little time with a medium stone should do the job. Sharpen just like you're sharpening.

If you try to strop, you'll damage the strop with a rolled edge. It's an edge pointing sideways/backwards. You don't want to drag that over your nice cotton/leather strop
View attachment 129717

I’m only stroping on a thick dry layers of green compound, so the rolled edge basically only Touching the green compound instead of dragging the leather. I definitely won’t try it on plain leather strop with no compound on it, liked you said it might potential cause the damage to the leather.

 

[Jason183]

I figured the whole edge has to go, I was more concerned about gouging my stone with that section pointing straight down while sharpening. I’ll give it a go on my SG500 and hopefully it’ll abrade off quickly.

I would recommend starting from higher grit stone first, see if you can knock the rolled edges off easily, the green compound I’ve used was equivalent to 6k grit stone.

 

[ModRQC]

Edge trailing, as low as you can, until the whole edge bevel looks right - a small burr should present consistently and fold side to side consistently. SG500 would do well at that indeed. Me personally I'd plateau that edge then with a very light 90* swipe across the stone, looking to start from a bit thicker and solidified foundation, but feel free to not do so.

Then sharpen with a rather conservative angle.

Mine Santoku had the same thing happening. Edge would fold under nail. Same with the Gyuto I had.

 

[ian]

Just put your garlic in a hard tupperware and shake the **** out of it till the skin comes off.

Don't worry too much about trimming the end and definitely use a knife thicker behind the edge if you want to roast some garlic and clip the bottom in the future.

Also, just be careful about cutting straight. Since the clove skin is hard and slanted, it’s easy to end up applying pressure on the edge that’s not in the spine to edge direction. I used to have problems with chipping or rolling with garlic cloves until @panda and @M1k3 told me to just pay better attention to my cuts.

i think your SG500 idea is just fine. Just sharpen at a pretty low angle until the problem’s gone, and then put a more conservative bevel on it. Idk why one would prefer edge trailing... I’d just sharpen however you usually do.

 

[Delat]

Since the clove skin is hard and slanted, it’s easy to end up applying pressure on the edge that’s not in the spine to edge direction. I used to have problems with chipping or rolling with garlic cloves until @panda and @M1k3 told me to just pay better attention to my cuts.

Ah, that explains it perfectly - I never thought about that cut being at an angle.

 

[ModRQC]

i think your SG500 idea is just fine. Just sharpen at a pretty low angle until the problem’s gone, and then put a more conservative bevel on it. Idk why one would prefer edge trailing... I’d just sharpen however you usually do.

Basically, starting from the side the rolled edge is protruding, a few strokes would manage to unfold the whole thing going into a regular burr. I just wouldn't go edge leading into that roll from the start. Not saying it wouldn't work though. The low angle is the key idea, rather.

 

[ian]

Hmm, seems like if the steel’s weak, you’re just trying to remove it rather than straighten it out, so that seems overcomplicated. Certainly can’t hurt tho. Maybe I’m oversimplifying.

 

[ModRQC]

Hmm, seems like if the steel’s weak, you’re just trying to remove it rather than straighten it out, so that seems overcomplicated. Certainly can’t hurt tho. Maybe I’m oversimplifying.

I see what you mean. Then again, in my own procedure, I deburr that quick work with a perpendicular stroke, having the new apex cleared of the weak/too thin steel. I'm into your view as long as the sharpener at hand is reminded the basic of applying pressure when trailing, and releasing when leading. And mostly reacted from the comment of using "only" edge leading, which I would entirely avoid in this case. But that's not experience talking, rather precaution. You've seen more than I.

 

[superworrier]

Also, just be careful about cutting straight. Since the clove skin is hard and slanted, it’s easy to end up applying pressure on the edge that’s not in the spine to edge direction. I used to have problems with chipping or rolling with garlic cloves until @panda and @M1k3 told me to just pay better attention to my cuts.

i think your SG500 idea is just fine. Just sharpen at a pretty low angle until the problem’s gone, and then put a more conservative bevel on it. Idk why one would prefer edge trailing... I’d just sharpen however you usually do.

Do you mean you cut an angle so it's perpendicular, or just that you're very careful?

 

[ModRQC]

Loosen up grip and pinch, let the knife go down through rather than forcing it straight downward. Cut will be about just as straight anyhow. Never had a problem out of a single clove of garlic, and I cut plenty.

 

[ian]

Do you mean you cut an angle so it's perpendicular, or just that you're very careful?

No, cut straight down with a fair amount of push or draw and just be careful that the knife doesn't deflect. Try to slice rather than using a lot of pressure.

 

[Delat]

Reporting back that you guys were right, it was super easy to grind down the folded edge section. Took less than a minute and maybe a dozen gentle edge trailing strokes on the SG500 and it’s gone. Now I need to bring the rest of the edge flush with the gap and create a fresh bevel, but that’s a project for the weekend. My initial worry was due to my main sharpening experience being VG10 and R2, but the SKD is a cakewalk in comparison.

I’m really happy I’ve been sticking with relatively inexpensive j-knives as I go through this learning process. I’d be freaked out if this knife had cost $500+. Makes me feel inclined now to recommend cheaper semi- or carbon-core knives to all the newbies like me buying their first j-knife and just learning sharpening.

 

[Hz_zzzzzz]

I have to say the hammer finished yoshi looks better than my yoshi with Najishi finish. Really nice choice for the first Japanese knife.

 

[nwshull]

Sometimes if you hit a particularly dense hard portion of the bottom of the bulb I have seen some damage occur. Its a freak thing, but it does happen.

 

[Hz_zzzzzz]

And Yoshi is thinner at the edge ootb than most other J knives no matter what price range it is. There are some other J knives that are comparably thin but it’s hard to get significantly thinner. The only other non-custom knife that I’ve had and is significantly thinner at the edge than my Yoshi was a Shig Kitaeji. And that Shig factory edge was sharp but it micro-rolled and micro-chipped like crazy. Even after I cleaned it up once it’s still chippy. Steels have their limits I think.

 

[ModRQC]

Reporting back that you guys were right, it was super easy to grind down the folded edge section. Took less than a minute and maybe a dozen gentle edge trailing strokes on the SG500 and it’s gone. Now I need to bring the rest of the edge flush with the gap and create a fresh bevel, but that’s a project for the weekend. My initial worry was due to my main sharpening experience being VG10 and R2, but the SKD is a cakewalk in comparison.

I’m really happy I’ve been sticking with relatively inexpensive j-knives as I go through this learning process. I’d be freaked out if this knife had cost $500+. Makes me feel inclined now to recommend cheaper semi- or carbon-core knives to all the newbies like me buying their first j-knife and just learning sharpening.

The gap?

Perhaps I should have specified that the motion needs applying to the whole profile, always.

 

[captaincaed]

Awesome man, glad the learning process is treating you right. And yea, that SKD is pretty nice stuff.