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Searching around google for information on grit numbers, I can only find tables like this -- Grit = Micron = Mesh Conversion Chart
Using a bit of maths, it seems to me that the size of the particles in microns can be calculated by 20'000 divided by the grit number (close enough anyway). Does that sound right?
It depends on whose grit is being considered. Different manufacturers use different scales and so different conversions apply.
In other words, a Norton 8k does not have the same size grit as a Naniwa 8k.
That would be just too easy.
That's a pity. Do you know anywhere I could get data on the various manufacturers?
It really won't do you any good. The material of the grit, grit size distribution, grit/binder ratio, binder material, all come into play. In the end you just have to see how a stone behaves.Quote:
Originally Posted by smolloy
I suppose you're right. Far too many unknowns. Thanks anyway!
Consider the Suehiro 20K with 0.50 micron "grit" size and the Shapton 30K at 0.49 micron. Bluesman hit the nail right between the eyes.
rs,
Tack
We've tried this before and as Utopian says it depends on the data you use, which in turn depends (it seems) on the manufacturer (and perhaps on their marketing division..!)
Just for some interesting reading, take a look at this thread from ages ago. I kinda went a bit overboard for some people's tastes, but perhaps you'll find it interesting...
And a good post about some of the important stuff around the behaviour of stones and grit: http://straightrazorpalace.com/honin...tml#post248353
James.
Thanks Jimbo, that fitting technique was exactly what I did to get my rule-of-thumb formula. The only difference is that I noticed that -0.9 was pretty close to -1, and so I re-did the fit forcing the exponent to be -1. After that I got a numerator of 20k instead of the 14.8k you got.
I realise now that this doesn't tell the whole story (not by half!), but it was at least fun doing the maths :)
(Yeah, I'm a huge nerd!)
No one ever made a more true statement than Glen's:Quote:
Originally Posted by bluesman7
"No amount of money spent on a Stone can ever replace the value of the time it takes learning to use it properly"
Here's a really good one that I found....
https://docs.google.com/spreadsheets...R-o/edit#gid=0
If you start searching for the meaning behind the grit and micron numbers on man made stones you'll end up with the impression we have on natural stones. Pretty much, they don't mean anything.
For Norton, 1 micron is 24k grit, as their 8k is 3 micron but not really, for Naniwa 10-12k is about 1 micron, for Sigma and Suehiro, 10k is 1 micron, and for lapping film and Shapton 15k is 1 micron.
Each company has its own scale, but the grit is closer to the finishing capabilities than the micron scale. It doesn't make sense since both describe the size of particles, but it's true. And you'll see some difference between the 8k from one company to the 8k of another, but they are not too far apart. In the end, what matters is if you are satisfied from the stones of a brand that you have. If not, follow the general advise here; Naniwa chocera 1k, and either 4/8 norton, or 3/8 naniwa superstone. For finishers, use a pasted strop or go for naturals is my opinion. Most of the man made finisher stones can be quite harsh for the skin.
i suck at math. i just use this chart as i only have to match the grid with the company style. Norton uses American standard. Naniwa uses JIS. Not sure about other stones but if you know the micron then you will have an idea of what it may be considered.Attachment 208445
