order of 10 2 mm or on the order of 10 1 mm at the maximum in this case the ptfe should also fill the small holes formed in the sheet like expanded graphite when the thus coated sheet like expanded graphite is heated at a temperature of 120 u00b0 c for several minutes the solvent is completely vaporized and with this treatment a ptfe film is formed on the surface of the sheet like expanded graphite so firmly that the film cannot be easily peeled off by a usual treatment also it is conceivable that as the ptfe a slurry form which is applied by mixing the minute powders of the ptfe sold under the trade name 34 ptfe fine powder 34 by mitsui fluorochemicals co ltd in water or volatile dispersing agent can be used but in this case a small amount of adhesive may be mixed or dissolved in the dispersing agent as described above the ptfe treated sheet like expanded graphite is combined with a metal mesh as a reinforcing material to form a laminate and the graphite is located on the sliding surface at the outermost layer of the laminate and in this case a metal mesh as a reinforcing material singularly or with a sheet like heat resistant material being put thereon can be interposed inside the assembly which constitutes the sliding surface alternatively in place of the metal mesh last.