As the most representative types of fluoroplastics, PTFE and PVDF deliver outstanding corrosion‑resistance properties. Among them, PTFE offers the best corrosion resistance of all known engineering plastics. It can be applied in environments with concentrated acids and concentrated alkalis, including hydrofluoric acid (HF) and fuming sulfuric acid as well as nitric acid (above 98%). It also exhibits favourable high‑temperature performance: PTFE is proven for continuous use up to 180 °C, whereas PVDF can withstand temperatures up to 150 °C. Nevertheless, PTFE features very low mechanical strength, poor dimensional stability and substantial thermal deformation. By comparison, PVDF provides better overall comprehensive properties. For bearings, inner and outer rings are typically made of PTFE or PVDF; the cage material is also PTFE or PVDF; balls are generally glass balls or ceramic balls.