Polytetrafluoroethylene (PTFE) is an engineering plastic which has uniquely low coefficient of friction, is chemically inert, an excellent electrical insulator and has good thermal stability.
Virgin PTFE machines well but clamping/holding the material can be a problem, and the application of excessive clamping force can damage the material. Other varieties of PTFE often come impregnated with fillers to improve this characteristic.
Due to its non-stick nature, it is very difficult to join PTFE using adhesives. While it is not impossible, extensive surface preparation must be carried out before specialist adhesives are applied. Note that regular adhesives will often form a bond, but the working life of this this is short lived with minimal disturbance required to break the bond.
Example application of PTFE maybe bearings, gears, sleeves, bushes and seals.