TC Skeleton Oil Seal — FKM Rotary Shaft Seal, ID 25–40mm, Multiple Sizes

Measure the shaft inner diameter (ID), the housing bore outer diameter (OD), and the groove depth (thickness) with calipers. Match all three dimensions to the variant you select. For example, a 30×50×8mm seal has a 30mm (≈1.18") ID, 50mm (≈1.97") OD, and 8mm (≈0.31") thickness. When in doubt, prioritize the shaft diameter first — a seal that's too tight on the shaft will leak.

These TC skeleton oil seals are made from FKM (Fluoroelastomer), commonly known by the trade name Viton. FKM generally offers superior resistance to petroleum-based oils, hydraulic fluids, fuels, and high temperatures compared to standard NBR (nitrile) seals, making it the preferred choice for demanding rotary shaft sealing applications.

FKM seals typically handle continuous operating temperatures from approximately -20°C (-4°F) up to +200°C (+392°F). This makes them suitable for most automotive gearboxes, hydraulic pumps, and industrial motors where heat buildup is a concern. Short-term peak temperatures may be higher — contact us to confirm for your specific application.

Yes. FKM material generally resists moisture, weathering, and many chemicals. The TC double-lip design adds a secondary dust-exclusion lip that blocks dirt, water, and debris from reaching the primary sealing surface — making these seals well-suited for outdoor machinery, agricultural equipment, and environments where contamination is a concern.

A TC seal has two sealing lips — a primary oil-retention lip and a secondary dust-exclusion lip — plus a metal skeleton for rigidity. An SC seal typically has a single lip. TC seals are generally preferred when both oil retention and contamination exclusion are needed, which is why they're the standard choice for gearboxes, axles, and pumps.

FKM seals are generally compatible with petroleum-based hydraulic oils, gear oils, and most mineral oils. They also typically resist synthetic hydraulic fluids better than NBR. Always verify compatibility with your specific fluid and operating conditions before installation, especially for specialty or synthetic fluids.

Clean the housing bore and shaft thoroughly. Lightly lubricate the seal lip with the fluid it will retain. Press the seal squarely into the bore using a seal driver or a flat plate — never hammer directly on the seal face. Ensure the seal sits flush or slightly below the housing face. Inspect the shaft surface for grooves or roughness that could cause premature wear.

TC skeleton oil seals are designed for rotary shaft applications. Actual maximum shaft speed depends on shaft surface finish, lubrication, and operating temperature. In most cases, these seals perform well at typical industrial and automotive shaft speeds. For high-speed applications, contact us to confirm suitability for your specific RPM and shaft diameter combination.