Thread: X Microns = Y Grit ?

I have been looking around the forum for a chart that can tell you the grit equivalence in microns. In other words I would like to see what a paste in microns would equal in sanding grit or vice a versa.

I'm just trying to figure out the honing/paste process and which grit/paste goes in what order.

Lynn answered one question saying that 0.5 microns is about 30k.

Thanks in advance.

It's here:

Formulae For Converting Between Grit and Microns - Straight Razor Place Wiki

You'll need a scientific calculator to use the formula. I can walk you through the keystrokes if you're unfamiliar with using the log functions.

Originally Posted by roughkype

It's here:

Formulae For Converting Between Grit and Microns - Straight Razor Place Wiki

You'll need a scientific calculator to use the formula. I can walk you through the keystrokes if you're unfamiliar with using the log functions.

Thank you very much for the link. Thanks on the logs but I'll pass. I might just break out my slide rule for old time sake!

OK, have fun. Slide rules are the straight razors of math.

Since I last posted, I worked out an Excel spreadsheet that will do the microns to grit and grit to microns conversions. PM me an e-mail address if you want it and I'll send it to you.

I got this one from a member a couple of years back. It is pretty close.



Estimated Microns = 14755 / Grit


The Wiki is right on but my brain just can't engage sometimes enough to use it.


Take Care,
Richard

Originally Posted by riooso

I got this one from a member a couple of years back. It is pretty close.

Estimated Microns = 14755 / Grit

The Wiki is right on but my brain just can't engage sometimes enough to use it.

Take Care,
Richard

The Wiki is completely unintelligible unless one has a background in statistical estimation (which I do).

And with that background, it doesn't make sense! The exponent β1 should be -1.000. That is, "grit" is inversely related to "microns". If β1 is _different_ from "-1", there's a problem with the data used to estimate it !

Also, the confidence intervals are quite broad, indicating a lot of "noise" in the data used for estimation.

The short formula above has the right exponent, and makes a heck of a lot more sense. I'll change it to:

Microns = 15,000 / Grit

for my own use.

Thank you!

Charles

PS -- there are roughly 25,000 microns to one inch. Based on the simple formula, I suppose that a "1 grit" particle would be about 5/8" in diameter. Not a ridiculous estimate.