Scary Sharp Vs. Stone Grit Size...?

Howdy,
I was perplexed because the resulting edge seemed so much better when I sharpened my leather working round knives on 2000 grit paper as compared with a 7000 grit waterstone.
But then I realized that I was comparing two different systems of grit measurement.
Do you know of some conversion system? That is, what paper grit size might be equivalent to a 7000 grit Japanese waterstone?
Sincere thanks,
--
Kenneth

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Among other places available with a search for grit comparisons, this is a good one http://www.marine.nortonabrasives.com/Media/Documents/S0000000000000001074/Coated%20Abrasive%20Basics.pdf because you can print it for your notebook or wall.
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wrote:

Hi George,
I thank you for that suggestion, and it is a useful resource, but (unless I am misinterpreting something) it does not go nearly fine enough for my needs.
All the best,
--
Kenneth

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Kenneth wrote:

What kind of sandpaper? 2000 grit FEPA is roughly 10 microns, while 2000 grit CAMI is around 1 micron but isn't as uniform (can contain larger particles that will leave stray scratches).
According to http://www.leevalley.com/wood/page.aspx?c=1&pF224&cat=1,43072 an 8000 grit waterstone should be around 1 micron.
Are you sure your waterstone was flat and that you polished to the same degree using both techniques?
Chris
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On Mon, 11 Feb 2008 11:26:18 -0500, Kenneth

Interestingly, I have been building an Excel spreadsheet with just that information. Most sources don't go smaller than 5 microns, so I took an existing table and added the smaller data from various sources. It may be useful to others. Note that there is some variation in different sources between what "CAMI" vs. "FEPA" vs. "Microns" and "Japanese" actually measures to.
Since rec.woodworking doesn't want binary attachments, I've attached a "CSV" file (means comma separated value, I think) that can be loaded into just about any spreadsheet program out there.
Since I don't know that rec.woodworking even wants that, I've also pasted the CSV information below. You could copy that and paste it into Notepad (or other plain text editor) and save it to a file, then load that file into your spreadsheet program.
Good luck
,CAMI Grit designation,ISO/FEPA Grit designation,Japanese,Average particle diameter (m),Examples Extra Coarse (Very fast removal of material),,P12,,1815, ,,P16,,1324, ,,P20,,1000, ,,P24,,764, ,24,,,708, ,,P30,,642, ,30,,,632, ,36,,,530, ,,P36,,538, Coarse (Rapid removal of material),40,P40,,425, ,50,,,348, ,,P50,,336, Medium (sanding bare wood in preparation for finishing),60,,,265, ,,P60,,269, ,,P80,,201, ,80,,,190, Fine (sanding bare wood in preparation for finishing),,P100,,162, ,100,,,140,Coarse Crystolon ,,P120,,125, ,120,,,115, Very Fine (final sanding of bare wood),,P150,,100, ,150,,,92,Medium Crystolon ,180,P180,,82, ,220,P220,,68, Very Fine (sanding finishes between coats),,P240,,58.5, ,240,,,53,Fine Crystolon ,,P280,,52.2, ,,P320,,46.2, ,,P360,,40.5,40 micron SiC paper Extra fine,320,,,36, ,,P400,,35,Extra fine scotch brite pad ,,P500,600,30.2, ,360,,,28,Washita oil stone ,,P600,,25.8, Super fine (final sanding of finishes),400,,,23, ,,P800,,21.8, ,500,,,20,Soft Arkansas stone ,,P1000,,18.3, ,600,,,16, ,,P1200,,15.3,"15 Micron belt, 15 micron SiC paper" Ultra fine (final sanding of finishes),800,P1500,2000,12.6,"Hard white Arkansas, extra fine diamond, and medium ceramic" ,1000,P2000,4000,10.3, ,,P2500,,8.4,"Hard black Arkansas, 9 micron belt" ,1200+,P4000,,5,5 micron SiC paper ,1500,P6000,6000,3,"Extra fine white Ceramic, green chrome rouge, 3 Micron belt." ,,,8000,2 or 3,Japanese Water stone ,2000,,15000,0.9,Japanese Water stone ,12000,,30000,0.5,"Chromium oxide polishing compound, 0.5 micron Chromium oxide paper, Shapton 30000 stone, diamond paste "
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You can post binaries at alt.binaries.pictures.woodworking and point to it in your replies here. Art
"Jim Weisgram" wrote

[snip]
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I once spent a fair amount of effort to resolve this exact issue. I compiled a spreadsheet, based on several sources, regarding the relative grit-size of the various grading systems. I'll post hte spreadhseets over on teh binaries group, with a bit of detail.
-Zz
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Excellent! Very much appreciated, sir.
*tips hat*
r
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