TC Skeleton Oil Seal Ring Rotary Shaft Sealing NBR Double Lip Seals ID 121-150mm

Measure three dimensions: (1) the shaft outer diameter — this becomes your seal ID; (2) the housing bore inner diameter — this becomes your seal OD; (3) the axial depth of the housing recess — this must be equal to or greater than the seal thickness. Cross-reference all three against the variant options listed on this page. If your shaft is 130 mm in diameter, select a seal with ID 130 mm, then match the OD and thickness to your housing.

"TC" designates a double-lip skeleton oil seal per ISO 6194 / DIN 3760 nomenclature. The primary (inner) lip retains lubricant inside the bearing cavity. The secondary (outer) lip acts as a dust and moisture excluder. A single-lip seal (type SC or R) has only the primary lip and offers less protection in dirty or wet environments. TC seals are the standard choice for most automotive and industrial rotating shaft applications.

NBR (nitrile butadiene rubber) performs well with petroleum-based mineral oils, greases, diesel fuel, and water-glycol hydraulic fluids in the temperature range of approximately −40°C to +120°C. It is not recommended for use with phosphate-ester hydraulic fluids, ketones, strong acids, or aromatic hydrocarbons. If your application involves synthetic esters or continuous temperatures above 120°C, consider an FKM (Viton) seal instead.

Clean the housing bore and lightly lubricate the seal OD with clean oil or assembly grease. Use a flat press plate or a seal driver of the correct diameter to press the seal in squarely — never hammer directly on the seal face. Press until the seal face is flush with or slightly below the housing surface. Lightly coat the primary lip with the same lubricant the seal will be retaining before sliding it over the shaft. Avoid dragging the lip over keyways or splines without a protective sleeve.

For optimal lip seal life, the shaft contact surface should have a hardness of 45–60 HRC and a surface roughness of Ra 0.2–0.8 µm (8–32 µin). Avoid lead-in chamfers with sharp edges; a 15–20° chamfer with a smooth radius is recommended. Shafts with deep circumferential machining marks, corrosion pitting, or wear grooves will cause premature lip wear and leakage. A shaft repair sleeve can restore a worn surface without replacing the shaft.

Yes. TC skeleton NBR oil seals in the 121–150 mm ID range are commonly used in agricultural tractor rear axles, PTO shafts, combine harvester gearboxes, and construction equipment final drives. Verify that the operating temperature does not exceed 120°C continuously and that the lubricant is a petroleum-based gear oil or grease compatible with NBR. For applications with heavy mud, water ingress, or abrasive dust, the dual-lip TC design provides better exclusion than a single-lip seal.

An OD that is too small will not achieve the interference fit needed for a static seal against the housing bore, resulting in leakage around the outside of the seal. An OD that is too large may crack the housing during installation or distort the seal body, compromising the lip geometry. Always match the seal OD to the housing bore within the manufacturer's specified interference range — typically 0.1–0.4 mm of radial interference for steel housings. Contact us to confirm if you are unsure about your housing bore tolerance.