Metric NBR Oil Shaft Seal Dust Grease Seal TC Double Lip w Spring ID 35-40mm

Measure the shaft outer diameter (this becomes the seal ID), the housing bore inner diameter (this becomes the seal OD), and the available axial depth in the housing (this determines the seal width). Cross-reference all three dimensions against the variant size matrix (ID × OD × Width in mm). If the housing bore is worn, measure it carefully — an oversized bore may require a repair sleeve or a seal with a slightly larger OD.

TC stands for a double-lip seal design: the primary lip retains lubricant (oil or grease) on the inboard side, while the secondary lip faces outward to exclude dust, dirt, and moisture. A garter spring behind the primary lip maintains consistent contact pressure against the shaft. This makes TC seals the standard choice for most automotive and industrial rotating shaft applications.

NBR (nitrile) is compatible with mineral-based engine oils, gear oils, hydraulic oils, greases, and water. It is not suitable for phosphate-ester hydraulic fluids (e.g., Skydrol), ketones, strong acids, or aromatic/chlorinated solvents. If your application uses synthetic esters or silicone-based fluids, consider a Viton (FKM) seal instead. When in doubt, check the lubricant manufacturer's elastomer compatibility data.

For reliable sealing, the shaft contact surface should have a ground or polished finish with a roughness of approximately Ra 0.2–0.8 µm (8–32 µin). The surface should be free of machining marks that run parallel to the shaft axis, as these can act as leak paths. Avoid using emery cloth in a back-and-forth motion; instead, polish in a circular direction. A hardness of 45–60 HRC at the contact zone is recommended for long seal life.

Clean the housing bore and lightly lubricate the seal OD with clean grease or oil before pressing in. Use a flat driver or a seal installation tool sized to the OD — never strike the seal face directly with a hammer. Press the seal in squarely until it is flush with or just below the housing face. Lightly coat the primary lip with the lubricant it will be sealing before fitting over the shaft. Protect the lip from sharp keyways or splines by wrapping the shaft end with thin tape or a cone during installation.

NBR TC seals are suitable for a wide range of shaft speeds, but the maximum peripheral velocity depends on the shaft diameter, lubricant viscosity, and operating temperature. As a general guide, NBR lip seals are commonly used up to approximately 4–8 m/s peripheral speed under normal conditions. For high-speed applications (e.g., above 6 m/s), verify with the application data or contact us to confirm suitability before ordering.

Both pack sizes contain identical seals — the same size, material, and specification. The 5-pack is priced at a lower per-unit cost and is practical for workshop stock, fleet maintenance programs, or assemblies that use multiple seals of the same size (e.g., both input and output shafts of a gearbox). Select your size first, then choose the pack quantity that suits your needs.