TC/SC/TG/SG

TC Oil Seal is a widely used rotary shaft seal designed to retain lubricating oil or grease while helping prevent dust, dirt and other external contaminants from entering the sealing system. Its typical structure combines a spring-loaded main sealing lip, secondary dust lip, rubber-covered outer diameter and internal metal reinforcement, making it suitable for many automotive and industrial rotating applications.

TBT supplies TC Oil Seal, SC Oil Seal, TG Oil Seal and SG Oil Seal in different dimensions and rubber materials for truck, transmission, axle, engine and machinery sealing applications. The correct type should be selected according to the sealing function, contamination level, housing condition, shaft size and operating environment.

TC Oil Seal Structure and How It Works

A typical TC Oil Seal consists of several functional components:

● Primary sealing lip – contacts the rotating shaft and helps prevent lubricating oil or grease from leaking out.

● Secondary dust lip – provides an additional barrier against dust, dirt, moisture and other contaminants.

● Garter spring – maintains consistent radial contact between the main lip and shaft as the seal operates.

● Rubber-covered outer diameter – improves static sealing between the oil seal and housing bore while helping compensate for minor surface irregularities.

● Metal reinforcement – maintains the shape and mechanical stability of the oil seal during installation and operation.

The double-lip structure is one of the main reasons buyers choose a TC Oil Seal instead of a simpler single-lip seal.

When Should You Choose a TC Oil Seal?

A TC Oil Seal is a practical choice when the application needs both lubricant retention and external contamination protection.

Consider TC type when:

● The rotating shaft must retain oil or grease inside the assembly.

● The equipment is exposed to dust, road debris or moderate external contamination.

● An additional dust lip is required to protect the primary sealing lip.

● The housing benefits from a rubber-covered outer diameter for improved static sealing.

● You need a common rotary shaft seal for automotive or general machinery applications.

TC seals are especially useful where a single sealing lip may not provide sufficient protection against contamination.

TC Oil Seal vs SC, TG and SG Oil Seal

Although TC, SC, TG and SG Oil Seals all belong to common radial shaft seal families, their lip and outer-diameter structures are different.

TC Oil Seal vs SC Oil Seal

The main difference is the number of sealing lips.

A TC Oil Seal uses a main sealing lip plus an additional dust lip, while an SC Oil Seal normally uses one primary sealing lip.

Choose TC when the equipment is exposed to dust, dirt or external contaminants. Choose SC when the operating environment is relatively clean and the primary requirement is lubricant retention with lower lip contact.

TC Oil Seal vs TG Oil Seal

Both TC and TG Oil Seals normally provide double-lip sealing and use an internal spring.

The difference is mainly in the outer-diameter design. A TC Oil Seal normally has a smooth rubber-covered outer surface, while a TG Oil Seal typically uses a grooved or corrugated rubber-covered OD.

TG may therefore be considered when the housing or installation design specifically requires this outer-diameter profile. For replacement applications, always confirm the original structure rather than selecting only by dimensions.

SC Oil Seal vs SG Oil Seal

SC and SG are generally single-lip structures. The SC Oil Seal typically has a smooth rubber-covered outer diameter, while the SG Oil Seal uses a grooved or corrugated OD.

If an existing seal is marked SG, replacing it directly with SC only because the ID, OD and width are the same is not recommended without checking the housing and original sealing structure.

Typical TC Oil Seal Applications

TC Oil Seals are commonly used around rotating shafts where lubricants must remain inside the equipment while the sealing area may also encounter external contamination.

Typical applications include:

● Truck and vehicle engines
● Crankshaft sealing positions
● Transmissions and gearboxes
● Axles and differentials
● Steering systems
● Pumps and motors
● Agricultural machinery
● Construction machinery
● General industrial rotating equipment

For truck and automotive replacement applications, buyers should also confirm the OE number, installation position and vehicle model when available.

How to Select the Right TC Oil Seal

Dimensions alone are not enough to identify the correct oil seal. Two seals with the same size can have different lip structures, compounds or operating characteristics.

Before ordering, confirm the following information:

● Seal size: Inner Diameter × Outer Diameter × Width
● Structure: TC, SC, TG, SG or existing seal profile
● Material: NBR, FKM or other required rubber compound
● Sealing medium: Oil, grease or other lubricant
● Application: Engine, gearbox, axle, transmission, pump, motor, etc.
● Shaft operating conditions: Speed and temperature
● External environment: Clean, dusty, wet or contaminated
● OE / part number: For replacement applications
● Vehicle or equipment model: When applicable

NBR or FKM TC Oil Seal?

Material selection should be based on the actual operating environment rather than only the seal dimensions.

NBR is commonly selected for general oil and grease sealing because it offers a practical balance of oil resistance, flexibility and cost.

FKM should be considered when the seal is exposed to higher temperatures or more demanding oil and chemical conditions.

The correct material should always be confirmed according to the lubricant, temperature and operating requirements of the application.

Why Choose a Double-Lip TC Oil Seal?

The main advantage of the TC structure is that it performs two functions at the shaft interface.

The primary lip keeps lubricant inside, while the secondary lip helps prevent outside contamination from reaching the main sealing area. This makes the TC Oil Seal a practical solution for rotating equipment where both leakage control and contamination exclusion are important.

However, TC is not automatically the best choice for every application. In a clean enclosed system, an SC Oil Seal may be sufficient. Where a grooved outer-diameter structure is required, TG Oil Seal or SG Oil Seal may provide a better structural match.

The correct seal should therefore be selected according to structure + size + material + operating conditions, rather than the type code alone.

Need Help Identifying a TC, SC, TG or SG Oil Seal?

If you are replacing an existing oil seal but are unsure about the exact structure, send us:

● OE or part number
● ID × OD × Width
● Photos of both sides of the existing seal
● Material requirement
● Vehicle or equipment model
● Installation position
● Operating conditions

TBT can help you identify a suitable TC Oil Seal, SC Oil Seal, TG Oil Seal or SG Oil Seal and evaluate standard or customized sealing options for your application.