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View Full Version : Can we summarize "toothy, "edgeiness," and slicing results on different foods?



GeneH
05-26-2013, 11:20 AM
I see a lot of posts where folks like toothy edges, smooth edges, and talk about how well the knife slices through ______. I also seem to see a lot less emphasis on refining blades down to 20k stones, and instead have great results at 2K or 4K.

My questions are: at about what grit / micron size stone gives the right toothiness and what effect does stropping after that have? Just burr or feather removal? Does a toothy edge seem to last (effective cutting ability) longer or just easier to get the knife sharp and move on?

When the edges of my knifes seem toothy, I'm almost afraid to use the 3-finger test, but when I refine the edge with 1 micron compound on a strop, the edges are smooth feeling, still frightening sharp but seemingly not as prone to cut into my finger - more controllable I guess is the way I would put it. What happens to veggies and other fruits or garlic or onions that are sliced with toothy edges compared to smoother edges? Does it affect the flavor?

I do realize this topic is really about personal preferences, and I expect opinions here from the fringe.... :D

chinacats
05-26-2013, 11:47 AM
I usually finish at 5k (Gesshin) which leaves plenty of 'tooth.' I can't even imagine why anyone would want a higher grit finish on a double bevel knife of any kind. I've yet to be cut myself on any edge with a 3 finger test, but if cutting fleshy items I would prefer the edge that feels a bit scary. When it feels slick you're more likely to slide across the food you are cutting and more likely to actually cut yourself. I understand single bevels to be a different story altogether but I have no experience there.

GeneH
05-26-2013, 11:59 AM
I understand single bevels to be a different story altogether but I have no experience there.

Good point: I am focused on symmetrical western double bevels, so I hope a lot of the discussion is relevant to double bevels.

Squilliam
05-26-2013, 12:22 PM
Recently I've given up the loaded strop for a 2k green brick finish + plenty of stropping on the textured side of leather for burr removal. I strop until the bite stops decreasing. In my mind, I have removed 99% of the burr, so the bite comes from the scratch pattern.
IMO mostly what people here talk about in regards to toothiness is actually a fine burr, not the scratch pattern.

This 2k edge is sitting on crossing the HHT threshold. No-one would complain that this isn't sharp enough, so taking it higher for a 80% loss of tooth and a 8% gain in sharpness does not seem worth it to me.

My opinion will change soon though, no doubt :)

Edit: I'm talking about carbon at 61 hrc here, I would probably take harder carbon finer, if I had it. Softer steel (euro) should probably be left with 2k burr :Beersausage: or a lower grit burr-free edge. Once it hits the steel though, it doesn't really matter. :2cents:

mhlee
05-26-2013, 12:41 PM
"Toothy", to me, means that you can still feel the "teeth" on the edge when slicing through foods. I think of "toothiness" or "edginess" as a level of feedback from the knife that I get from my knives.

FWIW, I'm a home cook, but like Chinacats, I totally agree about not finishing knives at higher grits. In fact, I can't say I've ever finished a double bevel knife above 6k ever. I've used a knife that was sharpened up to 10k+ but, to me, it felt like I had less control over the knife when doing more precise cuts.

I have single bevel knives that I've sharpened up to 6k and I feel that that's sufficient for single-bevel knives. I primarily cut fish with my single bevel knives, and I definitely don't want a knife that'll just glide through food with no feedback.

chinacats
05-26-2013, 12:43 PM
Good point: I am focused on symmetrical western double bevels, so I hope a lot of the discussion is relevant to double bevels.

If focused on symmetrical westerns you might need to specify as most J-knives (and likely most high end customs) are almost all going to be asymmetrical to some degree. Read this (http://www.kitchenknifeforums.com/showthread.php/5656-Asymmetry-%E2%80%93-The-REAL-DEAL)for background.

Cheers!

panda
05-26-2013, 03:06 PM
toothy = writing with a pencil
smooth = writing with gel ink pen

Crothcipt
05-26-2013, 09:23 PM
toothy = writing with a pencil
smooth = writing with gel ink pen

:plus1:

GeneH
05-26-2013, 09:35 PM
"Toothy", to me, means that you can still feel the "teeth" on the edge when slicing through foods. I think of "toothiness" or "edginess" as a level of feedback from the knife that I get from my knives..... I've used a knife that was sharpened up to 10k+ but, to me, it felt like I had less control over the knife when doing more precise cuts. ... I definitely don't want a knife that'll just glide through food with no feedback.

Then this observation I had is more or less incorrect- "smooth feeling, still frightening sharp ...more controllable I guess is the way I would put it...' and ya, the toothy edges seemed to want to take my finger off given half a chance. I like the analogy also from Panda, "pencil vs gel ink pen." Thank you for that.

psfred
05-27-2013, 02:58 AM
A coarse stone will leave a ragged edge from the scratches were individual abrasive grains removed metal. These scratches make a very fine toothed saw out of the edge when it is drawn across something (like a tomato) and will cut quickly. However, the edge is not really all that sharp, it's sawing it's way through whatever it is cutting, and if pressed down with no lateral motion, won't cut all that well.

As one progresses through finer and finer grits, the deep scratches disappear, and the shallower scratches from the finer and finer particles begin to make a nearly perfect planar edge. This edge will cut most things very easily, and excels at cutting soft things like raw fish neatly and effortlessly. No saw effect now, since as the blade approaches perfectly polished, the edge approaches a pure intersecting pair of planes with no "teeth" from scratches.

Cheapo crap knives almost always have a roughly ground edge, as the saw-like edge will cut decently if "sawn" through the food and won't lose "sharpness" quickly. It's not sharp, as one can easily prove by attempting to cut an onoin or tomato without "sawing" through.

The amount of "tooth" you want is a personal preference tempered by the material being cut and the style and material makeup of the knife in use. A very sharp, very hard Japanese single bevel knife will be very very sharp, have no tooth at all, and will slice raw fish into transparent slices with ease. May not work very well to cut up a chuck roast with membranes in it and may make a mess of celery since the vascular bundles are much harder than the surrounding tissue and a really sharp edge may not cut them anywhere near as well as a slightly rougher edge with lateral motion.

I'm a home cook, so what I do may not translate well to a professional kitchen, but I only go up to a 3000 grit stone with western style knives. I don't find a brighter polish to make any difference in performance at all, and two fewer steps while sharpening is a great time saver. I do polish my three cheapo "rescue" Japanese style knives since they seem to cut better when polished on an 8000 grit stone for a bit. Probably a difference in usage as they handle differently, but they seem to cut better with a true polished edge.

My advise, therefore, is to try a 3000 grit stone as the highest grit you use on your western knives and see if you like the result. On Japanese or Japanese style knives, polish at least up to 5000 grit and try them. You could leave them at 3000 and see if they cut well for you, but in the final analysis you will have to experiment to see what suits you.

Peter

cclin
05-27-2013, 05:36 AM
here is video for basic concepts of toothy vs. polished edge. double bevel knife(gyuto, santoku etc..) cuts a variety of products so it requires a toothy edge to be versitile. Yanagiba only slices raw or boneless protein so it can take the edge up to 12k & above.....sharppen a double bevel knife that high is pointless because edge won't last very long!!

http://www.youtube.com/watch?v=lqsbO1w8rXE

GeneH
05-27-2013, 07:33 PM
The descriptions plus the Eamon Burke video is very helpful, especially for a home hack. Now I have a better understanding of what I feel on the edge, and how my knives are reacting to, as Eamon demonstrated in the video, tomatoes vs carrots. What a great example. Often I cannot discern correctness between inaccurate preconceptions and actual hands on experience so your responses have really helped. I'll be able to play around now and see how my different knives perform with the foods I tend to use them on.

I only have 2 harder steel knives - recently purchased Tojiro DP 180 Gyuto and 120 Petty, both purchased to be my everyday go-to blades. The others are a 10 in Old Hickory carbon butcher knife, 12 in Chicago Cutlery chefs, and my fillet knives. What I didn't realize was how soft these other blades are. I sure wish I knew where my old boning knife was.

GeneH
05-27-2013, 07:37 PM
...This 2k edge is sitting on crossing the HHT threshold.

Oh, quick question, what is a "HTT threshold" ?

Benuser
05-27-2013, 08:19 PM
Oh, quick question, what is a "HTT threshold" ?
Hanging Hair Test
allows you to get an idea of an edge with bite. The relatively rough edge will catch or grap the hair, a polished edge won't.
That kind of edges are very spectular but won't last very long as they encounter a lot of friction. A reasonable compromise would be a thin 5k edge finished with a few very light 2k edge trailing (stropping) strokes, probably at a slightly higher angle.

tk59
05-27-2013, 11:02 PM
My 20k+ finished razors pass HHT. Bite refers to the ability of an edge to pierce smooth surfaces such as tomato skin. I've been sharpening a Devin swr gyuto on a worn 500 grit diamond plate followed by 1 micron diamond strop. The edge gets me all hot and bothered when I use it. It passes HHT also but I wouldn't shave my face with it.

Benuser
05-28-2013, 07:08 PM
With kitchen knives you may choose to remove in the progression all the scratches from previous stones, or not. If you do, you may obtain a very sharp, thin, highly polished edge that might lack what most of us will call bite.
If you don't remove all the scratches, you may gain in bite but you increase friction and durability.

GeneH
05-28-2013, 11:56 PM
We just finished filleting a dozen Crappie and a small pair of Large Mouth Bass tonight. My Marttiini knife held up ok on on the bones, but I did notice some loss after a couple fish. These I guess are very soft steel and I'm thinking (as was suggested on another thread) I should bevel them with about 400 grit and call it good, with a little stropping to maintain the edge. I just don't like trying to force a blade through bones. Once I get my kitchen knives purchased I'll be looking to something better for filleting panfish an Northern Pike.

K-Fed
05-29-2013, 12:19 AM
My favorite progression thus far is chosera 400, 1k, 5k ( rebutting on felt in between ) and finishing on a nakayama karasu with no finish stropping on the felt. Leaves a very tooth edge that easily shaves they seem to last me ages with maintenance being simple stropping/ touch ups on the nakayama. Really amazing edges for double bevel edges in my eyes.