A jack chain is a type of chain made of thin wire, with figure-eight-shaped links, and loops at right angles to each other. Jack chains are often used to suspend fixtures such as lights or signs, for decorative purposes, or as part of a cable lock.[1]
A jack chain can also be to a toothed chain for moving logs.[2]
A form of arm protection for the fifteenth century infantry soldier who, typically, was not dressed in plate armor but wore a padded arming jacket (“jack”) to protect his upper body was also known as a 'Jack chain'.[3][4]
