75% TFE and 25% glass fiber. Since glass has the least effect on chemical and electrical properties and adds greatly to mechanical properties of unfilled TFE, glass fiber compounds have the best balance of chemical, electrical, and mechanical properties of any of the filled TFE compounds. Glass-filled-TFE seals offer the advantages of the unfilled resin plus longer wear, higher thermal conductivity, increased dimensional stability, and lower cold flow. Used in applications such as bearings, gaskets, V-Rings, O-Rings, back-up rings, hydraulic ring seals, non-lubricated compressor rings, value seats, valve liners, swivel liners, thrust washers, lip seals, standoff and feed-through insulators, and other applications in the chemical, electrical, and mechanical fields. Tensile strength CD - 2700 PSI. Elongation CD - 250%. Initial hardness, Shore D - 63. Compressive strength CD (0.2% offset) 1240 PSI.