A slide plate is linear bearing such as may be part of the expansion joints of bridges, high temperature horizontal ducts of water-tube boilers and other mechanical or structural engineering applications. In each case one plate is fixed and the other slides on top as expansion or contraction occurs.
The plates provide a surface with a low coefficient of friction which can be attached to a supporting structure. This combination provides support while simultaneously allowing an object to move (slide) freely along the supporting surface.[1] The plate may be of polytetrafluoroethylene (PTFE), Lubrite[2] or steel according to the application.
Multiple design variations are possible but the most common example of a slide plate (in structural applications) has glass-filled PTFE bonded to a steel backing plate. In these applications a two-part system is used which has an upper element with the PTFE surface face-down and bearing on a lower element with its PTFE surface face-up.