PTFE-THREAD SEAL TAPES - made of pure, virginal PTFE, are extremely expandable, resistant to ageing, not subject to secondary hardening, and also fit into deep threads. The tape does not react with chemicals and is resistant even to the strongest acids and bases; only solved and melted alkaline metals, as well as fluorine, have a slight effect. There is no danger of corrosion, as PTFE is resistant to all caustic liquids used in industrial production.