A Brief History of Chainmail Armor
Overlapping rings might just save your life one day.

Chainmail armor in the Middle Ages was achieved through a process of creating wire from steel. Once the wire portion of the process was complete, the blacksmith would form them into little interlocking rings through the use of a hand-cranked machine. The most common form of chaim mail armor utilized an overlapping ring system in which rows of rings were interlinked for strength. Flat rings were thinner in one direction than the other, which meant that they had less of a tendency to open up when struck with the tip or side of a sword (blade). The chain mail metal heated and cooled quickly and was constructed over an open flame.

Inserting the actual rings into the mail was a rather tedious process requiring more than one person to help. About 40,000 rings were required to make one shirt of chainmail armor. Each single ring was connected to at least four others at any one time throughout the entire garment. Ultimately, the chain mail armor was only as good as the padding the wearer had underneath as the chainmail served the single purpose of shock absorption.

There were basically two types of chainmail armor during that time - flat and round ring mail. Round rings were good against swords but no so good against arrowheads, the flat rings excelled against those. But once 15th century rolled in, along with the new-fangled discovery of gunpowder in warfare, chainmail became obsolete. Some Turks, Persians and Indians still used chainmail armor even up to 100 years ago.