09-03-2017, 10:29 PM
Almost all of the knives I sharpen are your basic kitchen and pocket knives. No fine grain really hard super steel, just your basic blades. As far as I can tell, most of these are in the RHC 56-59 range.
The interesting thing is that, almost always, they end up right about 150 gf sharpness. It’s so predictable I hardly need to bother with a sharpness test. I don’t do anything special, just throw some belt on the Kally, sharpen, deburr and that’s what happens.
Even though they are all about the same hardness, it happens with different knives with steels of various names sharpened in the 15° - 20° bevel range. Abrasive coarseness does not seem to be a factor as I see the same results using a 600 grit sic belt or a 120 grit Cubitron belt. As long as the blade is well debured, they all seem to end up right about that sharp.
I have a friend that also sharpens using a Kally and he has noted the same thing. While I have discussed sharpening with him, whatever exact method he uses is of his own invention. I only mention it because I found the coincidence curious.
Mr. Mark recently posted, “Measuring initial sharpness of all three blades after the 140 Atoma showed I needed to be more careful and thorough about removing the burr. I was getting up to 230, and down to 150 on different parts of the blades. I tried two alternating passes per side +1-2*, and the apexes were clean and sharp. I could see the hint of microbevel with 10x, but they were way more uniform in the 150 range.”
There’s that magic 150 gf sharpness number again. Sharpen, deburr, and… surprise! ~150 gf. Mr. Mark mentioned the blade was a 4" Wharncliffe. I don’t know the exact model, but a quick Google search indicates RHC 57-59 on most of them.
Obviously with such a diminutive data set it would be foolish to even attempt to form any conclusions based upon it. Nonetheless, I’ve seen that happen so many times with my own sharpening and seeing other folks with basically the same results has me wondering.
Foolish speculation has me wondering if steel blades within the RHC 56 – 59 sharpness range, sharpened without any special effort, tend to be about 150 gf sharpness and generally not much sharper.
If there is anything to that, and I’m not saying that there is, I wonder if it has something to do with the metallurgy of the blade.
This could obviously be nothing more than utter blather, but I found it curious enough to bother to type all this stuff and post it.
The interesting thing is that, almost always, they end up right about 150 gf sharpness. It’s so predictable I hardly need to bother with a sharpness test. I don’t do anything special, just throw some belt on the Kally, sharpen, deburr and that’s what happens.
Even though they are all about the same hardness, it happens with different knives with steels of various names sharpened in the 15° - 20° bevel range. Abrasive coarseness does not seem to be a factor as I see the same results using a 600 grit sic belt or a 120 grit Cubitron belt. As long as the blade is well debured, they all seem to end up right about that sharp.
I have a friend that also sharpens using a Kally and he has noted the same thing. While I have discussed sharpening with him, whatever exact method he uses is of his own invention. I only mention it because I found the coincidence curious.
Mr. Mark recently posted, “Measuring initial sharpness of all three blades after the 140 Atoma showed I needed to be more careful and thorough about removing the burr. I was getting up to 230, and down to 150 on different parts of the blades. I tried two alternating passes per side +1-2*, and the apexes were clean and sharp. I could see the hint of microbevel with 10x, but they were way more uniform in the 150 range.”
There’s that magic 150 gf sharpness number again. Sharpen, deburr, and… surprise! ~150 gf. Mr. Mark mentioned the blade was a 4" Wharncliffe. I don’t know the exact model, but a quick Google search indicates RHC 57-59 on most of them.
Obviously with such a diminutive data set it would be foolish to even attempt to form any conclusions based upon it. Nonetheless, I’ve seen that happen so many times with my own sharpening and seeing other folks with basically the same results has me wondering.
Foolish speculation has me wondering if steel blades within the RHC 56 – 59 sharpness range, sharpened without any special effort, tend to be about 150 gf sharpness and generally not much sharper.
If there is anything to that, and I’m not saying that there is, I wonder if it has something to do with the metallurgy of the blade.
This could obviously be nothing more than utter blather, but I found it curious enough to bother to type all this stuff and post it.