Norton Stone Codes

[jeffbird]

Looking at Norton stones on ebay, there are a variety of letter codes used.

What do they signify and are certain older ones better made than current production stones?

 

[jeffbird]

Found this Norton resource. Page 7 has the letter codes for most of their stones. I used it to buy some new old stock stones from e bay for very low cost once the codes were deciphered.

Hope it helps someone in the future.

https://www.nortonabrasives.com/sga-common/files/document/Catalog-SharpeningStones-Norton200.pdf