Recent investigations have shown that SbSbS4 is a promising solid lubricant. It exhibits outstanding extreme pressure (EP) performance, and good antiwear behavior under laboratory test conditions. An investigation was undertaken to identify the mechanism by which SbSbS4 functioned when used as a lubricant in the dry powder form and as an additive to oils and greases. Friction and wear behavior of SbSbS^ was investigated using several different wear tests carried out in air at temperatures ranging from 20°C to 500°C.