Fisch 5mm - 10mm (1/4-Inch - 3/8-Inch) Deburring Countersink is suitable for use in metals and all types of wood for countersinking and deburring of bores. It works chatter and bur free creating a high quality surface. It can be reharpened with a grindstone at the breast in the hole. Made from cobalt high speed steel.
eBay