>All the talk below about diamonds and cast iron for sharpening got me thinking...... Where can I get cast iron. I opened up my Mc Master Carr catalog and found cast iron in the index.
I bought a 1" x 4" x 36" piece for $87.00 and 2 "grits" of diamond paste for $25.00 more. I plan on cutting the plate in 3 - 12" pieces, surface grinding them flat, and yee haa, a polishing we will go!!!!
Kind of expensive but I will have 6 surfaces to use.
I'm not sure what I will get but I should know next week when it arrives. I work in a toolroom so I plan on surface grinding it, after I cut it into 3 pieces.
>We tried simply milling plate and that did not work for 1 micron grit.. apparently the mill tears particles out of the cast iron and leaves a mostly micropitted surface. Very little contact with tool. Surface ground plates have worked fine.
>Bill, 1 micron is pretty fine. I get mirror bright finishes lapping carbide and hard steel with 9 - 12 micron (green) diamond. The reason I bring it up is finer - slower.