Different performances from different knives (steels) for a specific task.

[Perverockstar]

Hello people. This is kind of a long post asking for pointers/knowledge so, please, bear with me.

I have different knives at work with different steels at the core. I pretty much sharpen all of them the same way. Lift a burr on a Shun 1000 stone, deburr and strop. One particular knife gets arm shaving sharp, a Kyohei Shindo Bunka. I also own a Shindo Gyuto, a Manaka ATS34 Gyuto, a Makoto Kurasaki Ryusei VG7 Gyuto and a Shiro Kamo Sujihiki, among others. I just mention these ones for the sake of this conversation.

All the rest of them end up being still very sharp. They go through most produce effortlessly, except for one particular task.

When I need to small dice Flanksteak, I find it a lot easier with either the Manaka or the Makoto Kurasaki. When I use the Kyoheis or the Shiro Kamo, it takes me a lot more effort.

My process is filleting it, then I make julienne and I finally dice it.

What would be the reason for it? I don't think it could be just because of the SS vs carbon core, that doesn't make sense to me after some reflection on it.

It is worth mentioning that sometimes I do finish my knives on the 6000 side of the same stone. Specially the carbon ones, but it makes little to no difference for this.

Thank you for your help and guidance.

 

[Troopah_Knives]

I think you are right that the steel isn't the main issue here I would say the blade geometry is almost certainly the main factor. The geometry doesn't just determine things like how a knife will cut through the material but how easy it is to sharpen. If you want to get to the bottom of this I would recommend spending some time comparing how the grinds feel side by side, looking down the choil and seeing what parts are thin and which are thick, and even comparing some of the measurements with calipers. The answers might be there!

 

[Perverockstar]

I think you are right that the steel isn't the main issue here I would say the blade geometry is almost certainly the main factor. The geometry doesn't just determine things like how a knife will cut through the material but how easy it is to sharpen. If you want to get to the bottom of this I would recommend spending some time comparing how the grinds feel side by side, looking down the choil and seeing what parts are thin and which are thick, and even comparing some of the measurements with calipers. The answers might be there!

I will do that, thank you.

I'm also being told in a FB group that could also be on how my knives are finished when sharpened and that cutting meat benefits from a more toothier edge.

 

[Jovidah]

Is thickness behind the edge the same? I'd suspect this may play a role.
Personally, if you don't have tools to objectively measure it, I found that the easiest way to compare this is to just hold the knife between your thumb and index finger and just feel it.
Toothier finish could also be a factor - but only if you consistently sharpen different knives differently.

 

[Perverockstar]

Is thickness behind the edge the same? I'd suspect this may play a role.
Personally, if you don't have tools to objectively measure it, I found that the easiest way to compare this is to just hold the knife between your thumb and index finger and just feel it.
Toothier finish could also be a factor - but only if you consistently sharpen different knives differently.

The only difference would be that, sometimes, I finish my carbon knives on the 6000 side. That's it. All of them get the same angle and a 50/50, same pases on each side. I count how many passes I needed to get a burr on the right side, then I proceed to the other side. Deburr and strop. That's pretty much it.

Like I said, my Kyohei Bunka gets the sharpest. Like NASTY! That makes me wonder why my other Kyohei doesn't get as sharp...

 

[Blank Blades.]

The only difference would be that, sometimes, I finish my carbon knives on the 6000 side. That's it. All of them get the same angle and a 50/50, same pases on each side. I count how many passes I needed to get a burr on the right side, then I proceed to the other side. Deburr and strop. That's pretty much it.

Like I said, my Kyohei Bunka gets the sharpest. Like NASTY! That makes me wonder why my other Kyohei doesn't get as sharp...

Is the Kyohei thicker than the others?

For whatever reason i find that the edges i get on very thin knives to come out better. Maybe because it takes less time to apex, so im spending less time potentially rounding the apex just barely.

Either way. That could be an explanation.

If its not purely geometry. Heat treatment could come into play. I find softer steel doesn't tend to do as well supporting a very fine apex, its also harder to deburr and to be generally harder to get as sharp as harder steel. So it could be that as well.

Or even a combination of both.

 

[Perverockstar]

Is the Kyohei thicker than the others?

For whatever reason i find that the edges i get on very thin knives to come out better. Maybe because it takes less time to apex, so im spending less time potentially rounding the apex just barely.

Either way. That could be an explanation.

If its not purely geometry. Heat treatment could come into play. I find softer steel doesn't tend to do as well supporting a very fine apex, its also harder to deburr and to be generally harder to get as sharp as harder steel. So it could be that as well.

Or even a combination of both.

The opposite, both Kyoheis are some of my thinnest knives, at least behind the edge, Aogami #2 supposedly heat treated to 61-63hrc. Very hard and thin.

Maybe one has a little harder core than the other one?

 

[Jason183]

I will do that, thank you.

I'm also being told in a FB group that could also be on how my knives are finished when sharpened and that cutting meat benefits from a more toothier edge.

Toothiness is the key here, most stainless steel can get toothier than carbon steel if you finished at same grit, higher grit=less toothy. Try sharpen your carbon steel knives at lower grit to add toothiness.

 

[Troopah_Knives]

The opposite, both Kyoheis are some of my thinnest knives, at least behind the edge, Aogami #2 supposedly heat treated to 61-63hrc. Very hard and thin.

Maybe one has a little harder core than the other one?

Honestly, it could also be corrosion on your edge. The apex of low alloy steel blades can corrode fairly easily.

 

[Blank Blades.]

Honestly, it could also be corrosion on your edge. The apex of low alloy steel blades can corrode fairly easily.

This could make sense. I know ive seen knives dull from corrosion.

 

[Perverockstar]

Honestly, it could also be corrosion on your edge. The apex of low alloy steel blades can corrode fairly easily.

Nah, the knives are well taken care of and they perform great with other ingredients. It is just on the Flanksteak where they are outperformed.

Plus it is 3 knives the ones that just don't do it there... And it even happens when they just got a fresh edge.

 

[Blank Blades.]

Nah, the knives are well taken care of and they perform great with other ingredients. It is just on the Flanksteak where they are outperformed.

Plus it is 3 knives the ones that just don't do it there... And it even happens when they just got a fresh edge.

Well. It stands to reason. If thats the case.

The wear resistance of the other steels is likely what is making the difference.

 

[Perverockstar]

Well. It stands to reason. If thats the case.

The wear resistance of the other steels is likely what is making the difference.

Can be, yes. Still makes me wonder if it is exactly that. Or just the geometry, or something else...

 

[Blank Blades.]

Can be, yes. Still makes me wonder if it is exactly that. Or just the geometry, or something else...

If it was other situations it happened in, i would say it could be the geometry. But i know blades used for meat will do better with more wear resistant steels.

Also, generally speaking, a thinner knife is going to do better with edge retention. Provided the steel is able to support the edge during whatever application the knife is made for

 

[blokey]

Nah, the knives are well taken care of and they perform great with other ingredients. It is just on the Flanksteak where they are outperformed.

Plus it is 3 knives the ones that just don't do it there... And it even happens when they just got a fresh edge.

Corrosion doesn’t just mean rust tho, low alloy steel corrodes faster than high alloy especially in acidic food like meat, the edge could be rounded by constant corrosion.
https://knifesteelnerds.com/2019/01/21/does-acidic-food-affect-edge-retention/

 

[Perverockstar]

Corrosion doesn’t just mean rust tho, low alloy steel corrodes faster than high alloy especially in acidic food like meat, the edge could be rounded by constant corrosion.
https://knifesteelnerds.com/2019/01/21/does-acidic-food-affect-edge-retention/

Good to know. Thanks for the info.

In this case it also happens with a freshly sharpened edge though, like a mentioned.

 

[bsfsu]

Have you looked at the different finishes that your knives have? Maybe there is more suckation/stickation on your Kyohei Shindo knives vs others others due to the sandblasted/Kurouchi vs migaki?

What are the finishes on your knives?

 

[Perverockstar]

Have you looked at the different finishes that your knives have? Maybe there is more suckation/stickation on your Kyohei Shindo knives vs others others due to the sandblasted/Kurouchi vs migaki?

What are the finishes on your knives?

The Kurouchi is pretty much gone by now, but they are still kind of "slick" on the finish, I thin them a little bit every time that I'm gonna sharpen them.

The Manaka has tsuchime, but just at the top. It is a very tall blade. I don't know how you would call the finish on the wide bevel, but it is kind of polished. I guess it is a level of Migaki.

The Makoto is migaki at the top and with a very light Kasumi at the primary bevel.

 

[Benuser]

All of them get the same angle and a 50/50, same pases on each side. I count how many passes I needed to get a burr on the right side, then I proceed to the other side. Deburr and strop. That's pretty much it.

Why this preoccupation with having equal bevels on both sides? It only rarely corresponds to the optimal solution with a given knife, supposing the knife isn't used by both right- and left-handers. For an only user the best edge is the one that corresponds to the blade's geometry. Or do you use a jig system as the Edge Pro?

 

[Blank Blades.]

I have a dream that one day we will live in a nation where an edge will not be judged
by the symmetry of its bevels, but by the crispness of its apex....

 

[SwampDonkey]

I have several of the same knives and noticed the same. The Kyohei Shindo bunka gets silly sharp but isn't great on meat, though I rather like his gyuto for steaks and Sashimi. The Makoto Ryusei has a curvier profile than the Kyohei gyuto and while it isn't as thin behind the edge or get as wicked sharp it's a great slicer for meat. I always chalked this up to shorter height, the gentle belly, and wide bevel making it a better meat knife.

 

[Benuser]

I have a dream that one day we will live in a nation where an edge will not be judged
by the symmetry of its bevels, but by the crispness of its apex....

... and how well its geometry suits the blade's one. Otherwise even the apparently best edges won't address poor performance.

 

[Perverockstar]

Why this preoccupation with having equal bevels on both sides? It only rarely corresponds to the optimal solution with a given knife, supposing the knife isn't used by both right- and left-handers. For an only user the best edge is the one that corresponds to the blade's geometry. Or do you use a jig system as the Edge Pro?

I don't use a system. Just free hand. I like it 50/50 cuz that is what I have found that works for me.

Now, could you elaborate on which bevel "configs" work better for which geometry? How do you recommend approaching each one of them on the stones?

I'm willing to try again.

 

[Perverockstar]

I have several of the same knives and noticed the same. The Kyohei Shindo bunka gets silly sharp but isn't great on meat, though I rather like his gyuto for steaks and Sashimi. The Makoto Ryusei has a curvier profile than the Kyohei gyuto and while it isn't as thin behind the edge or get as wicked sharp it's a great slicer for meat. I always chalked this up to shorter height, the gentle belly, and wide bevel making it a better meat knife.

I do like my knives with a gentle belly and a wide bevel a lot more that my other's, I gotta say. But I do like them tall as well.

 

[Benuser]

I don't use a system. Just free hand. I like it 50/50 cuz that is what I have found that works for me.



Now, could you elaborate on which bevel "configs" work better for which geometry? How do you recommend approaching each one of them on the stones?

Almost no knife has both sides being a mirror image of each other. Have a look at vintage Sabs, Henckels or Sheffields. And most Japanese knives have an edge that's off-centered to the left, to improve food release for right-handers. Better let the right bevel follow the arc the right face forms. Avoid shoulders where bevel and face meet. They create unnecessary friction. Here a very fat knife, a yo-deba by Misono. Perhaps it makes clear what I mean about bevel and face forming a continuous arc on the right side — the left one on the photo.

Often it will be necessary to increase the angle on the left side to balance friction and reduce steering. A Basic Explanation of Asymmetry

 

[coxhaus]

I find my German knives, Henckels 4star, work well with limes for me. During the summer I cut a lot of limes for drinks and meat. They hold their edge well better than others I have tried.

 

[Delat]

I have a dream that one day we will live in a nation where an edge will not be judged
by the symmetry of its bevels, but by the crispness of its apex....

Let no knife be judged by the color if its ku,
but by the content of its steel