Abstract: The graphite fiber-reinforced fluororesin composite including 99 to 40 parts by weight of a fluororesin, e.g. polytetrafluoroethylene, and 1 to 60 parts by weight of a graphite fiber. The graphite fiber has a specific surface area of 0.6 to 25 m.sup.2 /g and, as determined by X-ray photoelectron spectroscopic analysis, (1) a surface atomic oxygen/atomic carbon ratio of 0.10 to 0.20, (2) a surface atomic halogen/atomic carbon ratio of 0.05 to 1.8 or (3) a surface atomic oxygen/atomic carbon ratio of 0.10 to 0.20 and a surface atomic halogen/atomic carbon ratio of 0.05 to 1.8. Such fiber may, for example, be obtained by subjecting a graphite fiber to oxidizing treatment, halogenating treatment, or oxidizing and halogenating treatments. The graphite fiber imparts high mechanical strength characteristics and wear resistance to the composite.

Abstract: The fluororesin composite material with high mechanical strength characteristics and wear resistance comprising 99 to 40 parts by weight of a fluororesin, e.g. polytetrafluoroethylene, and 1 to 60 parts by weight of a carbon fiber wherein the carbon fiber has an interplanar spacing d(002) of 3.36 to 3.45 .ANG., a c-axis crystallite dimension (Lc) of 35 to 400 .ANG. and an a-axis crystallite dimension (La) of 40 to 800 .ANG.. The carbon fiber obtained by heat-treating a precursor fiber, previously infusiblized or flame resistance-treated, in an inert gas containing 20 to 5,000 ppm of an oxygen-containing gas at a temperature of 2,500.degree. to 3,00.degree. C.