TC Skeleton Oil Seal Ring Rotary Shaft Sealing NBR Double Lip Seals ID 80mm-90mm

Measure three dimensions on your existing seal or housing: the shaft outer diameter (this becomes the seal ID), the housing bore inner diameter (this becomes the seal OD), and the housing groove depth (this becomes the seal thickness). Match all three to the variant options listed above. If your seal is worn, measure the housing bore and shaft directly rather than the old seal, which may have deformed.

TC is a standardised designation for a double-lip rotary shaft seal with a steel skeleton frame. The first lip (primary) seals against oil or grease leakage; the second lip (secondary) acts as a dust and contamination excluder. This two-lip design makes TC seals suitable for environments where both fluid retention and ingress protection are needed simultaneously.

NBR (nitrile butadiene rubber) is compatible with petroleum-based mineral oils, hydraulic fluids (HM, HV types), diesel fuel, greases, and water-glycol mixtures. It is not recommended for use with phosphate ester fluids, ketones, strong acids, or aromatic solvents. If your application uses synthetic esters or silicone oils, consider a Viton (FKM) seal instead.

For reliable sealing, the shaft surface in the contact zone should have a ground or polished finish with a roughness of Ra 0.2–0.8 µm (8–32 µin). Surfaces that are too smooth (Ra < 0.2 µm) can prevent the hydrodynamic oil film from forming, while surfaces that are too rough (Ra > 0.8 µm) accelerate lip wear. Avoid longitudinal machining marks — the shaft should be turned or ground with a lead-free finish.

Clean the housing bore and lightly lubricate the seal OD with the same oil used in the application. Use a flat-faced seal driver or a piece of flat bar stock slightly smaller than the housing bore to press the seal in squarely. Apply even pressure around the circumference — never hammer directly on the rubber lip or the seal face. Press until the seal is flush with the housing face or to the depth specified in your equipment manual. Lightly lubricate the primary lip before fitting over the shaft.

TC skeleton oil seals are designed primarily for dynamic rotary shaft applications where the shaft rotates inside the seal. They can also function in reciprocating (linear) applications at low stroke speeds, though dedicated rod seals are generally preferred for high-cycle reciprocating duty. They are not intended for static face-seal applications.

Maximum permissible shaft surface speed for standard NBR TC seals is typically 4–8 m/s (800–1,600 ft/min), depending on shaft diameter, surface finish, and operating temperature. At higher speeds, lip friction generates heat that can degrade the rubber compound. For high-speed applications above 8 m/s, consult the equipment manufacturer's specification or consider a PTFE-lipped seal variant.