TC FB Skeleton Oil Seal Nitrile Rotary Shaft Seal Double Lipped NBR 70 ID-28mm

Measure the housing bore diameter (this becomes your required OD) and the depth of the seal groove or housing recess (this becomes your required height). All seals in this listing share a 28mm inner diameter — match the shaft size first, then confirm OD and height against your housing. When in doubt, consult the equipment service manual for the specified seal dimensions.

The inner (primary) lip faces the lubricant side and maintains contact with the rotating shaft to prevent oil or grease from escaping. The outer (secondary) dust lip faces the atmosphere side and acts as a barrier against dirt, water, and contaminants entering the bearing area. The TC double-lip design provides this dual protection in a single seal.

NBR 70 nitrile performs well with conventional petroleum-based oils, mineral hydraulic fluids, and many ATF formulations. It is generally not recommended for use with ester-based synthetic oils, phosphate-ester hydraulic fluids, or fuels with high aromatic content, which can cause swelling or degradation. If your application uses a fully synthetic or specialty fluid, verify fluid compatibility with NBR before ordering.

Clean the housing bore and shaft thoroughly before installation. Lightly lubricate the seal lip with the same oil or grease used in the application. Use a flat press tool or a seal driver sized to the OD to press the seal in squarely — never hammer directly on the seal face. Press until the seal face is flush with or just below the housing surface. Avoid dragging the lip over sharp shaft edges or keyways; use a lead-in chamfer or protective sleeve if needed.

TC-profile nitrile seals are suitable for moderate shaft speeds typical of gearboxes, pumps, and electric motors. For very high peripheral shaft speeds (generally above 4–6 m/s depending on seal diameter and surface finish), a PTFE-lip or hydrodynamic seal may be more appropriate. If your application involves sustained high RPM, contact us with your shaft diameter and RPM to confirm suitability.

For a single repair, the 1-piece or 2-piece pack is the most cost-effective option. If you service multiple machines with the same shaft size or run a fleet maintenance program, the 5-piece or 20-piece pack reduces the per-unit cost significantly. The 20-piece pack is particularly suited to shops that perform regular gearbox or pump overhauls where this seal size appears frequently.

After pressing the seal in, visually confirm it sits flush and square in the bore with no visible tilt. Run your finger around the outer edge to check for any gap between the seal OD and the housing. Before reassembling the unit, rotate the shaft by hand and check that the lip maintains even contact. After initial run-in (typically 15–30 minutes of operation), inspect the seal area for any signs of weeping or leakage.