| Function |
Seals fluid or gas between two mating parts |
Seals lubricants in and contaminants out (e.g., in rotating shafts) |
| Type |
Static or dynamic |
Dynamic (usually rotating) |
| Material |
Rubber (NBR, Viton, Silicone, etc.) |
Rubber with metal case, sometimes PTFE or polyurethane |
| Design |
Circular cross-section, installed in a groove |
Lip seal with spring-loaded lip for shaft contact |
| Application |
Hydraulic, pneumatic, and general sealing |
Gearboxes, engines, motors, and rotating equipment |
| Installation |
Simple groove fit |
Housed in a bore, seals against a rotating shaft |