Metal quality, attention to perfection, Biggest Sharpness Benefits?
- This topic has 3 replies, 4 voices, and was last updated 02/11/2017 at 10:15 am by
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I’ve always focused on the number of strokes it takes to remove the scratches from the previous grit, but that’s not necessarily the best way to an optimum edge. I believe that each grit will leave some degree of roughness along the edge, regardless of the number of strokes taken. It’s the job of the next grit to remove that roughness and to leave no more roughness than it is capable of producing. Carry that through with each grit of your progression and you’ll find the degree of sharpness will be optimized. Check the edge with your microscope on hi-power and see what’s really happening.
That said, the degree of sharpness perceived by the user is heavily influenced by the thinness of the blade at the shoulders of the main bevel, the included angle of the bevel and the level of polish thereon (within limits). For kitchen work, I find that a thin blade (< 0.015″) makes for the most noticeably sharp edge. Whether or not you need a micro-bevel depends on the material you will cut with it.
For best results I recommend holding the handles near their bottom ends. When the pressure applied moves above the edge, there is a shift in the angle at the point where the stone touches the bevel. But for most people, I think the key is simply absolute consistency. Do it the same every time. But keeping your fingers below the edge is also good practice from a safety standpoint.
I never had anyone complain about an edge I had sharpened with 800’s, but then, I don’t charge $ for it, so they don’t dare complain. I remember being amazed at the edges I sharpened to 600-grit before I got my 800/1000s.
I have no clue about Japanese molybdenum.
Basically, I’d say it’s all
. But the steel and your technique are very important.Molecule Polishing: my blog about sharpening with the Wicked Edge
Given a constant sharpening scenario, the type of steel is a driving factor in edge sharpness and durability. Equally important, in my amateur opinion, is the heat treatment differences that different bladesmiths will use on a given type of steel (ie. not all 52100 knives will sharpen the same). It is not a trivial exercise to determine what combinations work best but it can surely be interesting.
Google the “Verhoeven – Metallurgy of Steel for Bladesmiths”. It is a 200 page excellent paper written in a similar manner to Verhoven’s Experiments in Knife Sharpening on the WEPS website Download section. It starts with “What is Steel” and takes you thru the alloys and full heat treatment scenarios. It is too big to paste here but someone who knows how should get it to the Downloads section of the WEPS website.
Kitchen knives and sharpening is my hobby. The best chef’s in the world understand what combining ingredients and heat will do to a dish. Similarly, the best bladesmiths in the world would also. I went to a Bob Kramer sharpening class once and held one of his custom $5,000 52100 steel chef knives. As weird as it sounds, you could feel the greatness of the knife by holding and examining it.
Is there a metallurgist among us who would be interested in discussing the science behind grain size and the like ? Other forums tend to get into “what I do is best” scenarios.
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