PTFE Oil Seals & High-Performance Rotary Shaft Seals

PTFE oil seals combine the structural retention of a stainless steel outer case with the exceptional material properties of a polytetrafluoroethylene sealing lip. PTFE is chemically inert to virtually all industrial fluids, stable from cryogenic temperatures to +260°C, and capable of running with minimal lubrication or in intermittent dry contact. These characteristics make PTFE oil seals the preferred choice for process pumps, chemical compressors, semiconductor equipment, cryogenic expanders and high-speed spindles where conventional rubber seals would harden, swell, degrade or generate excessive friction. The PTFE lip is typically manufactured as a thin, flexible wafer or ribbon energized by a metallic garter spring or an elastomer secondary seal. The spring maintains contact pressure against the shaft despite PTFE's lack of elastic recovery. Some designs use a PTFE lip bonded to an elastomer backing ring, combining the chemical resistance of PTFE with the elasticity of FKM or NBR. Filled PTFE grades—with carbon, graphite, glass or MoS2—improve wear resistance, thermal conductivity and dimensional stability in aggressive dynamic service. Stainless steel cases are standard for PTFE oil seals because they resist the corrosive media commonly found in PTFE applications. The case provides a press-fit in the housing bore and protects the thin PTFE lip during installation. Shaft hardness and surface finish are critical for PTFE seal life: a hardened shaft above 55 HRC with Ra 0.1–0.4 µm and no circumferential marks gives the best results. Unlike rubber, PTFE does not recover from deep scratches on the shaft, so counter-surface quality is more important. Our PTFE oil seals are supplied in standard inch and metric sizes and can be manufactured to custom dimensions, lip angles and spring loads. Common applications include magnetic-drive pumps, cryogenic valves, chemical agitators, dry-running compressors, semiconductor wafer handling equipment and food-processing machinery requiring FDA-compliant materials.