TB2 Oil Seals - Durus

What Is a TB2 Oil Seal?

TB2 is a hybrid configuration: the bare-metal Type B case (chamfered steel OD) of a TB seal combined with the Standard double lip (primary lip with garter spring + auxiliary dust lip) of a TC seal. The result is dust exclusion suitable for dirty environments combined with the bare-metal OD preferred for hard precision housings. TB2 fits where TB falls short (dust exposure) and where TC isn't needed (rubber OD coating not required).

Construction summary:
Case Type: B (bare metal)
Lip Configuration: Standard double lip

When to Choose TB2

• Hard precision-bored housings combined with dusty operating environments
• Heavy equipment with cast iron seal cavities exposed to construction or mining dust
• Industrial gearbox external positions where the housing is well-machined but the environment is dirty
• Replacement for failing TB seals where dust contamination caused the original failure

When NOT to Choose TB2

• Soft housings (aluminum) - choose TC with rubber-coated OD instead
• Clean environments where the simpler TB single lip is adequate
• Marginal bore tolerance where the rubber coat of TC would compensate

Related Seal Types

Frequently Asked Questions

What is the difference between TB and TB2 oil seals?

Both use the same Type B bare-metal case construction. The difference is the lip configuration. TB has only a primary single sealing lip - appropriate for clean environments. TB2 adds an auxiliary dust lip outboard of the primary lip, providing dust exclusion for dirty environments while keeping the bare-metal case construction. Choose TB2 when you need dust exclusion in a hard housing where TC's rubber coat is unnecessary.

When should I specify TB2 instead of TC?

Specify TB2 when the housing is hard material (cast iron, steel) with a precision-bored seal cavity that doesn't require the bore-tolerance accommodation of TC's rubber coating, but the operating environment still exposes the seal to dust. Common application: industrial gearbox shaft positions in clean-machined housings used in dusty plant environments. For soft housings or marginal bore finish, TC remains the better choice.

Is TB2 more expensive than TC oil seals?

TB2 is typically slightly less expensive than TC for the same size due to the simpler bare-metal case construction (no rubber coating step in manufacturing). However, the cost difference is small and should not drive the selection - choose based on housing material (hard for TB2, soft for TC) and bore tolerance (tight precision for TB2, variable for TC). Texas Belting stocks both - call (888) 203-2358 for current pricing comparison on a specific size.

Can TB2 seals be used in dusty outdoor applications?

Yes, with consideration for the housing material. TB2's dust lip provides equivalent dust exclusion to TC. The choice between TB2 and TC for outdoor service depends on whether the equipment housing is hard-bored (TB2 acceptable) or has softer machined surfaces (TC preferred for installation tolerance and corrosion protection of the case). For most outdoor industrial equipment with cast iron housings, either type performs equivalently.