I have various diamond files but some that I use are chainsaw
sharpening diamond files that fit into a power drill. I have three
sizes 1/8, 3/16, 1/4 I remove the guides for the chainsaw sharpening
process and use the bits themselves either in a drill press or by
hand. They are excellent for shaping lathe tools. Also the long
steel chainsaw files in the same sizes. They are parallell! Very
useful for recessing hinges in boxmaking.
David Cruickshank Australia