SYNOPSISFluorinated (FKM) vulcanizates were treated by immersing in an aqueous solution of triazine thiols, NaOH, and onium salts for 15-60 min at 50-95OC ( W-Method). Treated FKM vulcanizates further were postcured in an air oven for 20 h at 200°C to complete the reaction. The onium salt of triazine thiols were found to be formed by a reaction among the triazine thiols, NaOH, and onium salts and to act as cross-linking agents to the surface of FKM vulcanizates. In the acetone solution of onium salts of triazine thiols, FKM vulcanizates were also treated by immersing for a few minutes at 20°C and then by heating in an air oven for 20 min at 200°C ( A-Method) . Triazine thiols were introduced as crosslinks onto the FKM backbone. The degree of cross-linking in the surface increased by these treatments and the depth of cross-linking reached up to about 40 pm thickness by control of treating conditions. The coefficient of friction in FKM vulcanizates decreased as a result of the surface treatment up to about 0.5 from 2.6. FKM vulcanizates decreased the tensile strength by these surface treatments because of the generation of cracks on the surface at 50% or 100% elongation. The surface treatment of FKM vulcanizates suppressed markedly the fixing between FKM vulcanizates and stainless steel at 150°C. Especially, the A-Method was very effective treating for retarding the fixing between FKM vulcanizates and metals.