TC NBR Skeleton Oil Seal Rings Double Lip Sealing ID 30~70mm, for Rotation Shaft

Measure three dimensions on your existing seal or housing: inner diameter (ID) — the shaft diameter the seal rides on; outer diameter (OD) — the bore in the housing the seal presses into; and height (also called width or thickness). Match all three to the variant listed as ID × OD × Height in mm. If your seal is worn, measure the housing bore for OD and the shaft for ID, then confirm height with a caliper on the old seal or housing depth.

TC is a standard oil seal profile designation indicating a double-lip design with a metal skeleton (casing). The primary lip seals against lubricant leakage, while the secondary lip acts as a dust and debris excluder. The metal skeleton provides structural rigidity for press-fit installation into a housing bore. TC seals are among the most common types used on rotating shafts in automotive, agricultural, and industrial equipment.

NBR (nitrile butadiene rubber) performs well with petroleum-based engine oils, gear oils, greases, and hydraulic fluids — the most common lubricants in rotating shaft applications. It is not recommended for use with brake fluid (DOT 3/4/5), phosphate ester hydraulic fluids, or ketone-based solvents. If your application involves these fluids, a Viton (FKM) seal would be more appropriate. For standard gearbox, engine crankshaft, or pump shaft sealing with mineral oil, NBR is a suitable choice.

Clean the housing bore and shaft thoroughly before installation. Lightly lubricate the seal lip with the same oil or grease used in the application — this prevents dry-start damage. Press the seal squarely into the bore using a flat driver or seal installation tool sized to the OD; never strike the seal face directly with a hammer. Press until the seal face is flush with or slightly below the housing face. Protect the primary lip from sharp shaft edges or keyways during installation using a sleeve or tape.

For reliable sealing, the shaft surface in the seal contact zone should have a surface finish of approximately Ra 0.2–0.8 µm (8–32 µin). Surfaces that are too rough accelerate lip wear; surfaces that are too smooth can reduce the hydrodynamic film that lubricates the lip. Avoid longitudinal machining marks — these can act as leak paths. If the shaft shows a wear groove from the old seal, reposition the new seal slightly axially to contact unworn material, or use a shaft repair sleeve.

Yes. The TC double-lip design addresses both functions in a single seal. The primary (inner) lip, loaded by a garter spring, maintains consistent radial contact pressure against the rotating shaft to retain lubricant. The secondary (outer) dust lip runs with light contact or near-contact to exclude dirt, water, and particulate from reaching the primary lip. This makes TC seals well suited for equipment operating in dusty or wet environments such as agricultural machinery, outdoor power equipment, and vehicle axles.

Common indicators include visible oil weeping or leakage around the shaft where it exits the housing, oil staining on adjacent components, or grease contamination inside a sealed bearing cavity. On disassembly, a seal that shows a hardened, cracked, or permanently deformed lip, a broken or corroded garter spring, or a lip worn into a groove pattern should be replaced. Seals that have been exposed to incompatible fluids may show swelling or softening of the rubber compound.