Metal-impregnated carbons have higher strength values (materials for sliding faces and stationary seats) than resin-impregnated synthetic carbons. The thermal limit of application is set by the melting point of lhe metal and/ or the base material carbon graphite or electrographite. Any local overshooting of the melting temperature in the area of the sliding face gives rise to streaky smears. Resistance to chemicals depends on which metals are used. Antimony is generally chosen as metal for the impregnation of face materials.