TC Skeleton Oil Seals ID 115–125mm | FKM Rubber Dual Lip Rotary Shaft Seal

Measure three dimensions: (1) the shaft outer diameter — this is your ID; (2) the housing bore inner diameter — this is your OD; (3) the housing depth — this is your Thickness. Match all three to the variant listed as ID × OD × Thickness. For example, 120*150*12mm fits a 120mm (≈4.72″) shaft in a 150mm (≈5.91″) bore with a 12mm (≈0.47″) housing depth. When in doubt, measure twice and contact us to confirm before ordering.

These seals use FKM (fluoroelastomer) rubber — the same compound family as Viton® — bonded to a steel skeleton. FKM generally offers superior resistance to heat, petroleum-based oils, synthetic gear oils, hydraulic fluids, and many chemicals compared to standard NBR (nitrile) seals. This makes them a better choice for high-temperature gearboxes, engines, and industrial machinery where NBR seals tend to harden and crack prematurely.

FKM rubber typically handles continuous operating temperatures from approximately -20°C (-4°F) up to 200°C (392°F). Short-term excursions may be tolerated at higher temperatures depending on the specific compound. Always verify against your application's peak operating temperature before installation.

Yes. The TC dual-lip design includes a primary sealing lip to retain lubricant and a secondary exclusion lip to block water, mud, and airborne contaminants from reaching the bearing or gear cavity. This makes them generally suitable for agricultural equipment, construction machinery, and outdoor power equipment where environmental contamination is a concern.

FKM seals are generally compatible with most petroleum-based oils, synthetic gear oils, automatic transmission fluid (ATF), and mineral hydraulic fluids. They are not typically recommended for use with ketones (MEK, acetone), certain esters, or DOT 3/4 brake fluid. When in doubt, verify fluid compatibility with the FKM material data sheet or contact us before installation.

For optimal sealing performance, the shaft contact surface should typically be ground or polished to Ra 0.2–0.8 µm (approximately 8–32 µin). Shaft hardness of HRC 30 or above is generally recommended to minimize lip wear over time. Rough or corroded shaft surfaces will accelerate lip wear and reduce seal service life significantly.

Follow these steps for a clean installation: (1) Clean the housing bore and shaft contact area. (2) Lightly coat the seal lip with the fluid being sealed (oil or grease). (3) Press the seal squarely into the bore using a seal driver or flat plate sized to the OD — never strike the seal face directly with a hammer. (4) Ensure the seal sits flush or slightly below the housing face. (5) Protect the lip from keyways, splines, or sharp edges during installation using a sleeve or tape.

A TC seal has two sealing lips (dual lip) with a garter spring on the primary lip — the most common type for general oil retention and dust exclusion. A SC seal is a single-lip design without a dust lip, used where only oil retention is needed. A TA seal is similar to TC but without the garter spring. For most gearbox, axle, and pump applications, TC is the in most cases the correct choice.