TC Double Lip Oil Seals NBR Rotary Shaft Seals — ID 8–50mm, H=7mm

Measure three dimensions: the shaft diameter (this becomes your ID), the bore diameter in the housing (this becomes your OD), and the groove depth (this is the height, H). All seals in this listing have H=7mm. Match your shaft to the ID column — for example, a 25mm shaft typically uses a seal with ID=25mm. If you only have inch measurements, multiply by 25.4 to convert to mm (e.g., 1" = 25.4mm, so a 1" shaft is closest to the 25mm ID option).

TC skeleton oil seals are generally designed for low-to-medium pressure applications. They are typically rated for static pressures up to approximately 0.05 MPa (≈7 psi). For higher-pressure hydraulic circuits, a dedicated hydraulic rod or piston seal is recommended. These seals are best suited for gearbox, pump shaft, and crankshaft applications where the primary function is retaining lubricant rather than resisting high fluid pressure.

NBR (nitrile rubber) offers good resistance to petroleum-based oils, water, and mild weather exposure, making it generally suitable for outdoor use in moderate climates. The secondary dust lip on TC seals provides additional protection against water ingress and dirt. For extreme UV, ozone, or aggressive chemical exposure, FKM (Viton) seals are typically recommended instead.

TC seals have a double lip design — a primary sealing lip that retains oil and a secondary dust lip that keeps contaminants out. SC seals have only a single lip. TC seals are generally preferred for applications where both oil retention and dust/moisture exclusion are needed, such as gearbox output shafts, wheel hubs, and agricultural equipment drivetrains.

All dimensions listed are metric (mm). If your equipment uses imperial shafts, convert the shaft diameter to mm by multiplying by 25.4, then select the closest matching ID. For example, a 1-inch shaft = 25.4mm, so a 25mm ID seal is typically the closest match. A 1/2" shaft = 12.7mm, closest to the 12mm ID options. When in doubt, contact us before ordering.

NBR TC oil seals are generally rated for shaft surface speeds up to approximately 4–8 m/s depending on the shaft finish, lubrication, and operating temperature. A smoother shaft finish (typically Ra 0.2–0.8 µm) and adequate lubrication at the lip will extend seal life. Consult your equipment manual to confirm compatibility with your application's RPM and shaft diameter.

Clean the housing bore and shaft thoroughly. Lightly lubricate the seal lips with the fluid being sealed (e.g., a thin film of gear oil or grease). Press the seal squarely into the bore using a seal driver or a flat block — never hammer directly on the seal face or lip. Ensure the primary lip faces the oil side (inward). Avoid nicking the lip on sharp shaft edges; use a chamfer or installation sleeve if needed.