Quote Originally Posted by khaos View Post
http://www.nortonconsumer.com/upload...ms%20Flyer.pdf
Here they claim Norton 8000= Japan (JIS) 8000.

I see what you mean....

Like I said earlier, almost all manufacturers have different ways of measuring things, but in Norton's case I think it is bad information:

The Old Japanese Industrial Standards method was with the sedimentation tube method of separating grit, and the 2000 grit rating was 8.5 micron but with an acceptable variation of +/- 0.7 micron.

The New Japanese Industrial Standards method is by electrical resistance of the grit in suspension, and the 2000 grit rating is 6.7 micron but with an acceptable variation of +/- 0.6 micron.

The Norton sheet you have posted (which is the same sheet I got Norton's grit to micron ratings from) shows the "JIS" rating to be 7.5 micron, and as you can see above is not covered by the acceptable variance by either standard unless they were simply giving a rough median of the old and new standards combined.....which seems the most likely explaination of their listed information.


The main problem with being exact with grit ratings is that people like me that want to know EXACTLY what something is, are an extremely rare breed. Most people are content to simply call every "8000" stone an 8000 grit and assume they are the same or close enough, and they are content with that. Here on SRP and a few other places I have found others like myself that are more interested in comparing apples to apples and making sure that every possible variable is as closely monitored as it can be, so that our conclusions about a given problem are actually based on fact and not just a wild guess.

Let us know what Henckles says about the stone, I for one would be interested in the information and would like to add it to the list if it is good stuff.