Carborundum grit question?

I just purchased a lot of stones on ebay wich included a two sided stone "Carborundum No. 109 SIC" and I was wondering if anyone could tell me the grit rating of either side coarse/fine?


Thanks
Louis.

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Originally Posted by Louis

I just purchased a lot of stones on ebay wich included a two sided stone "Carborundum No. 109 SIC" and I was wondering if anyone could tell me the grit rating of either side coarse/fine?


Thanks
Louis.

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I too would be interested to see if there is any kind of guide for converting the Carborundum numbers into their approx grit values