The Spyderco files are on the order of 1000 - 1200 grit. It will work but is probably slow going by hand. I'd be tempted to find some alumina or zirconia ceramics, such as an insulated electrical standoff, and chuck it in a drill. If you want to cut faster, the alumina grinding bits at Widget Supply http://www.widgetsupply.com/page/WS/...-ao-cylinder-1
are hard enough, but also harder to control.

Rick