The ST is a guitar bridge used on various hard-tail Ibanez models. It is designed by Ibanez and produced for Ibanez by Gotoh.
The ST is a Tune-O-Matic style bridge. It is solely a bridge, meaning that it does not anchor the strings to the body itself. Therefore it must be combined with a separate tailpiece or in a string-through-body setup. It was often paired with a Quik Change tailpiece or a Stop tailpiece.
The ST is mounted to the guitar top with a pair of posts threaded into studs glued into the body (or center block for semi-hollow guitars). Each post has a thumbscrew set midway onto which the bridge rests. The height of the bridge (and thus, the action of the strings off the fretboard) can be adjusted by screwing these posts in or out with the thumbscrew. The bridge has six individual saddles each of which supports one string. The position of each of these saddles can be adjusted fore and aft to achieve the correct intonation. This adjustment is made using screws in the side of the bridge.
The ST was largely replaced by the Gibraltar II when that model was introduced in 1983.