the scavenging of hundreds of them strikes me as being more trouble than it's worth. Brass or enameled copper wire can be used for edging although these materials, being somewhat soft, tend to unbut rather easily. Period mail links are generally of a 'D' or flattened cross section. Don't worry about this; it just means your mail will be slightly over weight. (Anyone getting close enough to spot this is more likely to tell you it isn't riveted!) There is no set size, per se , for links. Medieval rings vary from suit to suit with even armours from the same period and district being made from different sized links. The mail maker, regardless of the period of the person being portrayed, is therefore free to choose whatever size of link he finds appealing. The appearance of the finished mail article will depend upon the thickness of the wire used and the diameter of the former upon which the links are wound. The following table shows what sized links can be made from a given wire thickness. I have also included a conversion from millimetres to inches to help people who cannot think metric. Wire Size Ring Size Gauge Diameter of Wire Minimum Maximum Recommended (SWG) (mm) (mm) (mm) (mm) (in) 13 2.3 9 18 14 9/16 14 2.0 8 16 13 1/2 16 1.6 7 13 8 to 10 5/16 to 3/8 18 1.2 4 10 7 1/4 19 1.0 2 8 5 3/16 Ring size is internal diameter