TAJ ENTERPRISES What are master links used for? A master link is a chain accessory that provides convenient connection and disconnection of a chain without the need of a chain tool. In lifting, a master link is used when making sling assemblies and any number of rigging connections. Master Links and Master Link Assemblies are also known by other names including oblong links, head rings, multi-master link assemblies etc. They are one of the oldest types of forged lifting tackle and they sit at the apex of multi-leg lifting slings. There are two kinds of master links. The first kind is a straight-chain line-compatible link, often seen on single-speed and hub-geared bikes. The other is a derailleur-compatible external link.