Is a Kasumi finish a drag?

[Newbflat]

Observation of the moment. It’s been a long time since Ive had clad knives. Most of my knives are mono steel except for a few beater Shuns, and a few of Asai VG-10 I have (nice knives). Over the last few months I picked up a Mazaki 240 KU and a Mazaki 210 stainless clad, both gyuto’s. I have spent a fair bit of time playing with the finish on the bevel. I have worked the bevel with most of my medium and fine synthetic stones and three different J-Nats of fine-ish to very fine stones. In the end I have come to the conclusion that anything but a near mirror finish adds drag when cutting. With some finishes in some food a lot drag. I have never experienced this in any of the mono steel knife I have. While a Kasumi finish is pretty, I’m finding it less that appealing on the performance front. Anyone else have this issue?

 

[andrewlefilms]

I've had the same experience with very smooth kasumi finishes as well, especially with wet products. I find that hairline finishes, like you would find on a watanabe or the spine to edge satin finish on stamped blades have the best balance of aesthetic and performance, or any textured finish like KU or nashiji.

 

[ma_sha1]

I think there’s at least two factors at play, the grind vs. surface smoothness. When I had two Mazakis, one had flat bevel grind which amplified surface drag. If it’s nice convex grind like Kato WH, surface plays a minor role as convexity reduces surface contact. In a cheaper flat grind, surface plays a bigger role in drag.

 

[milkbaby]

I think there’s at least two factors at play, the grind vs. surface smoothness. When I had two Mazakis, one had flat bevel grind which amplified surface drag. If it’s nice convex grind like Kato WH, surface plays a minor role as convexity reduces surface contact. In a cheaper flat grind, surface plays a bigger role in drag.

I agree about these observations, i.e. it's not just about the finish but the grind too.

 

[Newbflat]

I get it about the grind helping mitigate some of the drag, but that’s not my point. People spend a lot of time nitpicking grind, weigh, steel types that are almost imposable to tell the actual difference in, profiles, taper and dismiss one knife over another because of it while obsessing about performance. But a Kasumi finish has a huge effect on the over performance convex grind or not and not a good one. Is it worth such a performance hit just for aesthetics?

 

[Matt Zilliox]

i will have to play some with this idea. my 2 easiest cutters have kasumi finishes, they fall through food. will have to pay closer attention

 

[ian]

Mirror finish is also not optimal, though, since food sticks like crazy to it.

Maybe what people are pointing out is that if you are playing with finishes on your bevel, you probably have flattened the bevel. Your monosteel comparisons that you cite in the OP do not have flat bevels, so it's hard to actually make a comparison of finishes.

That said, I've also noticed some grippyness from low grit kasumi finishes (eg King 800). I don't really notice it when I do kasumi with my uchimugori (3k-4k? I don't know for sure).

The real solution is to buy iron clad knives, give them a nice kasumi, and then let it patina! Patina is my favorite finish.

 

[Newbflat]

One Mazaki, the stainless one has pretty flat bevels. The KU one not so much. I sharpen both with the intention of making them more convex over time. I agree a polished surface has some stiction with say a thinly sliced cucumber, it’s not the drag/friction of a kasumi finish. Just drag you fingernail from the Hagane onto the jigane. My 5 or so mono steel gyuto’s are flattish at least on one side. What started me playing with the texture of the kasumi finish was taking my Mazaki 240 KU with a finish on the jigane from a Rika 5000 and tried to cut a block of cheese in half. It got half way threw and stopped like like it was glued in place. I un wedged it and grabbed my Hiroshiro 270 and it went threw like butter. I played with the Mazaki and the cheese and it was very apparent that it was ‘bonding’ to the finish on the jigane and was hard to remove it. Not so with the Hiroshiro, at least not nearly to the sane extent. I did a side by side comparison slicing some raw beef with the same knives and finish and it was obvious how much more drag there was with the finish on the Mazaki. So I have been playing with the finish since and I’m still working on something I’m happy with. I’m thinking of using my Kitayama today and work a slurry until it’s very dry for a bright polish and see if that helps.

 

[chinacats]

A drag to maintain...