Expanded PTFE (Teflon) gasket material is produced by expanding Virgin PTFE using a process that creates a uniform and highly fibrillated microstructure with equal tensile strength in all directions. This means that expanded Teflon possesses no structural weakness or a "grain".

PTFE gaskets are used in equipment handling chemicals and petrochemicals because they are resistant to corrosive fluids and extreme temperature extremes. Except for certain alkali metals and fluorine compounds, PTFE demonstrate resistance to most chemicals at various pressures and temperatures.