Chain Mail (or maille) is a type of flexible armour developed in the middle ages. It was made from a piece of wire. The wire is made into rings approximately one to two centimeters in diameter. Five rings are selected and four are closed, either riveted, welded, or just bent together, and slipped onto the fifth, which is then closed. This process is repeated, and another ring is slipped over two rings on one piece and two rings on the other, which is then done again and the two double pieces are linked together.
I made a small collar of chain mail for myself. It took me three or four days. I used 16 guage galvanized wire from Ace Hardware.