TC Oil Seal 300–380mm ID Rotary Shaft NBR Dual Lip Seal — Multiple Sizes

You need three measurements: shaft outer diameter (= seal ID), housing bore inner diameter (= seal OD), and housing depth (= seal thickness). For example, a 350mm shaft installed in a 390mm bore housing that is 20mm deep requires a 350*390*20mm seal. Always measure with calipers rather than relying on worn part markings. If you are between sizes, contact us before ordering — using an undersized ID or oversized OD will cause installation failure or leakage.

Quick inch reference: 300mm ≈ 11.81" | 350mm ≈ 13.78" | 380mm ≈ 14.96"

TC indicates a double-lip skeleton oil seal. The primary (inner) lip contacts the rotating shaft to retain lubricant. The secondary (outer) dust lip faces outward to exclude dirt, water, and debris. This dual-lip arrangement is generally the standard for gearboxes, axle hubs, and industrial shaft housings where both contamination exclusion and oil retention are required simultaneously.

TC skeleton oil seals are designed for low-pressure dynamic sealing, typically rated for static pressures up to approximately 0.05 MPa (0.5 bar / ~7 psi). They are not suitable for high-pressure hydraulic circuits. If your application involves significant internal pressure, a different seal type with a backup ring or a hydraulic rod seal is generally recommended. Contact us to confirm suitability for your specific system pressure.

NBR rubber generally performs well in outdoor conditions involving water splash, mud, and petroleum-based lubricants — making it a common choice for agricultural equipment, construction machinery, and marine auxiliary shafts. However, NBR is not recommended for prolonged exposure to ozone, direct UV radiation, or aromatic/chlorinated solvents. For those environments, a Viton (FKM) seal material is typically more appropriate.

NBR is generally compatible with most mineral and Group II/III petroleum-based gear oils. Compatibility with fully synthetic PAO or ester-based gear oils varies by formulation — some synthetic additives can cause NBR to swell or harden over time. If your gearbox uses a fully synthetic lubricant, verify NBR compatibility with your oil supplier's data sheet, or contact us to discuss alternative seal materials.

For reliable lip seal performance, the shaft contact surface should typically have a finish of Ra 0.2–0.8 µm (approximately 8–32 µin). Surfaces that are too rough will accelerate lip wear; surfaces that are too smooth may not retain the thin oil film needed to lubricate the lip. Shaft hardness of HRC 30 or above is generally recommended at the seal contact zone to resist wear grooving over time.

1. Clean the housing bore and shaft contact area thoroughly and remove any burrs.
2. Lightly coat the seal lip with the same lubricant used in the application.
3. Apply a thin film of oil or sealant to the outer diameter if the bore is dry.
4. Use a seal driver or flat press plate sized to the OD — press squarely and evenly until the seal face is flush with or slightly below the housing face.
5. When sliding the seal over the shaft, protect the lip from keyways or splines using a thin plastic sleeve or tape. Remove the sleeve after the seal passes the obstruction.