valve stem packing is made from 100% Virgin PTFE. It is a round, soft & high tensile strength material. can be used in a wide variety of applications, including Valves and Faucet stems, rotating shafts, reciprocating plungers, stuffing boxes and flanges Temperature Range-268~316 Pressure (kgf/cm2) Fluid sealing 200 Gas sealing 140 Diameter Range 2mm-20mm Density0.8 (g/cm3) Suitable medium : most chemicals except molten alkali metals and elemental fluorine