Sharpening Product grit conversions???

No expert but here is a link with a chart. http://www.ameritech.net/users/knives/norton.htm. I am not sure that I agree with it. I find warterstones in general give a smoother finish compared with the chart. You can't go by color.

I think the thing about waterstones is the slurry gets broken down and becomes finer. Well maybe.

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Roger Blake
 
Marion, fine / coarse etc., are not standard terms. For example 800 grit Japanese waterstones are advertized as giving a "coarse" finish and should be used for reprofiling and to remove damaged edges. Yet a 600 grit DMT hone is referred to as a fine stone.

You can standardize all hones by referring to the abrasive grit size or the average scratch depth. However this is rarely done. I have some tables showing abrasive grits sizes lying around, most from Lee Valley, I'll see if I can't find them when I get home.

-Cliff
 
Even grit sizes are different from different manufacturers -- greatly different; one manufacturer's 400 grit might be coarser than another manufacturer's 220 grit. "Fine" could mean anything. Also, diamond behaves differently than silicon carbide or aluminum oxide, cuts like it's much coarser than the grit size.

Whenever I buy abrasives I feel it with my thumb. The thumb test is more consistent than labels....



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-Cougar Allen :{)
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This post is not merely the author's opinions; it is the trrrrrruth. This post is intended to cause dissension and unrest and upset people, and ultimately drive them mad. Please do not misinterpret my intentions in posting this.
 
Really not an expert here! However, I do find that autobody sand paper does seem fairly consistent from company to company. A 400, 600, or 1200 from A, B or C, usually feels the same across the board. As this stuff is pretty cheap, it's a good 'feel' guide for comparison purposes. It's amazing how the human thumb can 'tell' how gritty something is compared to another, especially at those ranges. Carbide, diamond and aluminum wet papers... weird how I still call it all 'sand' paper...

Just ranting...

[This message has been edited by RLR (edited 02-24-2000).]
 
Beam, no maybe about it. The slurry that is produced from water stones polishes the metal. That's why if you're trying to cut quickly you need to remove the slurry. When you reach your final grit you let the slurry build up and polish the blade.

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"Better to reign in Hell, than serve in Heav'n"
John Milton
There are only two types of people; those who understand this, and those who think they do.
 
Well I'll admit that the difference in rating systems screwed me up at first.I was wanting a good bench sized fine stone to use between my hard arkansas and fine white ceramic. I almost spent about $35 on a surgical black arkansas that should have been about the equivalent of my ceramic, instead I saved $20 and bought a 1000 grit japanese stone. It was wrapped in plastic so I couldn't feel it, and the diamond stones they had only went to 600, so I thought I was getting what I wanted. Then I got home and tried to polish an edge out on it. Man did it eat that edge fast. Its the coarsest stone I have.
I did alot of reading on it after that. I can't remember the site but I found one with a full conversion chart that rated arkansas, diamond,ceramic, and japanese stones by both grit and what stage they should be used for.
If I remember right. 1000 grit japanese rates a little coarser than soft arkansas. Then hard arkansas is close to 4000 japanese I think (this is all from memery) Surgical black arkansas and I think 8000 grit japanese both rate close. And then above that fine white ceramic rates with a grit size of 4.5 to 5 microns. After that you get into compounds. I think green jewelers rouge has a grit size of .5 microns.
I hope I remembered it all correctly,and that it helps answer your question.

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Fix it right the first time, use Baling Wire !
 
It it just me but on the chart above it shows the DMT green (superfine) equivilent to better than a 4000 jap waterstone. No way. Maybe the slurry thing.

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Roger Blake
 
I must have threw out my Lee Valley catalogue, when I get a new one Marion I'll drop you an email with the information. It would be nice if this information could be added to the FAQ. The only thing missing from Lee Valley's table is on ceramics.

As noted above though even if you know the grit size of the abrasive particles, that will not lead to a direct relationship to smoothness of finish. If the particles can fracture they will self-smoothen and give a much finer finish. This is why everyone rates Diamonds as giving a coarse finish even when the grit size is very small.

-Cliff
 
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