Sterling Seal & Supply, Pure Teflon O-Rings are highly resistant to extreme chemical attacks and have a high resistance to the degrading effects of exposure to such solvents as acetone, MEK, and xylene Temperature Range: -300° to +450°F. Hardness (Shore A): 98, high resistance to ozone Sterling Seal & Supply TFE O Rings possess average elastomer characteristics of 2,500 to 3,500 psi tensile strength, and 300% elongation, they are tough, impact resistant, low friction, non-twisting performers over an extremely wide temperature range Special care must be taken during handling and installation of PTFE seal. They wont stretch fit as traditional elastomeric O Rings Because of its poor tear resistance, during O-ring installation particular care should be taken to avoid nicking or scratching Teflon, as imperfections will cause O-ring leakage