I've been looking for a while for exactly what this means. This is the designation for a stone currently sitting on my desk.

I know that Carborundum stones go by the numbers from about #102 on upwards, with the lower numbers being finer grit. I haven't, however, been able to find anything like a chart or list of conversions into grits, microns, JIS, etc. Does anyone know one, or the rough equivalences of #112?

Thanks in advance.