TC Oil Seal 30-35mm ID NBR Double Lip with Spring — Metric Shaft Seal

Measure your shaft's outer diameter — that becomes the seal's ID. Then check the housing bore for the OD, and measure the groove depth for the width. For example, a 30mm shaft in a 50mm bore with a 10mm groove needs a 30×50×10mm seal. When in doubt, match the width to your housing depth — typically 7mm, 8mm, 10mm, or 12mm for this size range. Using calipers gives the most accurate reading.

TC-type oil seals are generally designed for low-to-moderate pressure applications. They are typically rated for shaft surface speeds up to around 4–8 m/s and static pressures up to approximately 0.05 MPa. For high-pressure hydraulic circuits, a different seal type is recommended. These seals are well-suited for gearboxes, differentials, pumps, and wheel hubs operating under normal conditions.

NBR offers good resistance to water, mild weather exposure, and petroleum-based fluids. For prolonged outdoor UV exposure or saltwater environments, a Viton (FKM) seal is generally a better choice. These NBR seals work well in protected outdoor equipment such as gearboxes, wheel hubs, and agricultural machinery that sees regular but not extreme environmental exposure.

NBR is compatible with petroleum-based oils, hydraulic fluids, gear oils, greases, water, and diesel fuel. It is generally not recommended for use with brake fluid (DOT 3/4), ketones, esters, or strong acids. Always verify compatibility with your specific fluid before installation if you are working with non-standard lubricants.

TC seals have two sealing lips — the primary lip retains oil and the secondary dust lip keeps contaminants out. They are the right choice when the shaft is exposed to dirt, dust, or moisture. SC (single lip) seals are typically used in cleaner environments where only fluid retention is needed. For most automotive, agricultural, and industrial applications, TC is the standard and recommended choice.

The garter spring maintains constant radial pressure of the primary lip against the shaft, compensating for lip wear and minor shaft runout over time. Yes — the spring is pre-installed inside the seal. No separate assembly is required; just press the seal into the housing and you're ready to go.

Minor shaft surface imperfections can accelerate lip wear and cause early leakage. For best results, the shaft surface finish should generally be in the range of Ra 0.2–0.8 µm. If the shaft shows visible scoring or grooves, consider using a shaft repair sleeve before installing a new seal. Installing a new seal on a damaged shaft is one of the most common causes of premature seal failure.