SB Oil Seals - Durus

What Is a SB Oil Seal?

SB combines the bare-metal Type B case (chamfered steel OD, no rubber coating) with the S-style single lip configuration. The result is a minimal-friction single-lip seal in a tight-fit metal case - appropriate for clean environments in hard, precision-bored housings where the rubber coating of an SC type is unnecessary and a dust lip is not required.

Construction summary:
Case Type: B (bare metal)
Lip Configuration: S-style single lip

When to Choose SB

• Clean operating environments (sealed gearboxes, indoor equipment)
• Hard precision-bored housings (cast iron, steel)
• High-speed shaft positions requiring minimal friction
• Interior positions in multi-seal configurations (outer seal handles dust exclusion)

When NOT to Choose SB

• Soft housings (aluminum) - bare-metal case can score the bore
• Dirty environments with dust exposure (use SC, SB2, or TC instead)
• End-of-shaft positions where contamination directly contacts the seal

Related Seal Types

Frequently Asked Questions

What is an SB oil seal?

SB is a Durus designation for a Type B bare-metal case combined with the S-style single lip configuration. The case has a chamfered metal outer diameter (no rubber coating) for tight press-fit in hard precision housings. The S-style lip is a single primary sealing lip with garter spring - no auxiliary dust lip. SB is appropriate for clean operating environments in metal housings where minimum friction and lowest cost are priorities.

What is the difference between SB and TB oil seals?

Both use the same Type B bare-metal case construction. The difference is the primary lip design. TB uses the Standard lip configuration; SB uses the S-style lip configuration. In practice, both provide single-lip sealing with similar performance characteristics. The S-style lip in SB is engineered for slightly different load characteristics and is the preferred designation in certain OEM specifications. Cross-reference the original equipment part number to determine which designation matches.

Can SB oil seals handle dusty environments?

No - SB is a single lip seal without dust exclusion. For dusty environments, choose SB2 (same case with added dust lip), SC (rubber-coated case with single lip + dust lip), or TC (full rubber coat with double lip). SB is appropriate only for clean operating environments where the seal's outboard side is protected from contamination - typical examples include interior positions in sealed gearboxes or indoor equipment.

When should I use SB instead of SC?

Choose SB when the housing is hard material (cast iron, steel) with a precision-bored seal cavity - the bare-metal case provides a tight fit without needing the bore tolerance accommodation of SC's rubber coating. Choose SC when the housing is soft (aluminum, plastic) or has variable bore tolerance. Both use the same S-style primary sealing lip; the choice is driven by housing material and bore precision.