Here is my variant on making solid dome washers. I use a 2-56 bolt and nut. The inside diameter of a 2-56 nut is just about right for a 1/16 rod. I use a portion of the tube out of a Bic ballpoint pen as a spacer to keep the nut away form the chuck. Basically I chuck the bolt in the drill and file and sand the nut to shape. Make sure you go in the tightening direction when you are filing and sanding.
Charlie