The Timken Company 8521S Radial Shaft Oil Seal

Description:

The Timken National 8521S oil seal is a premium radial shaft oil seal engineered to retain lubricants while preventing the ingress of dirt, dust, moisture, and other contaminants in rotating equipment. Constructed with a durable nitrile sealing element, the 8521S features a springless multi-lip design that provides dependable sealing performance in industrial, automotive, agricultural, and heavy-duty applications. Commonly installed in gearboxes, wheel hubs, axles, pumps, electric motors, and power transmission equipment, the National 8521S is widely used by maintenance teams, OEMs, and system integrators for equipment repairs, seal replacements, retrofit projects, and preventive maintenance to maximize equipment reliability and reduce lubricant loss.

Applications:

The Timken National 8521S oil seal is designed for rotary shaft sealing applications where effective lubricant retention and contaminant exclusion are essential. Its springless multi-lip construction makes it suitable for industrial gearboxes, agricultural machinery, heavy-duty axles, wheel-end assemblies, pumps, compressors, electric motors, and other rotating equipment operating in demanding industrial environments.

Technical Specifications:

• Manufacturer Part Number (MPN): 8521S
• Manufacturer: Timken National
• Product Type: Oil Seal
• Seal Type: Radial Shaft Oil Seal
• Series: 8000 Series
• Seal Design: Type 200E (Springless Multi-Lip)
• Material: Nitrile (Buna-N) Rubber
• Shaft Diameter (ID): 1.872 in (47.55 mm)
• Housing Bore Diameter: 2.684 in (68.17 mm)
• Outside Diameter: 2.701 in (68.61 mm)
• Overall Width: 0.544 in (13.82 mm)
• Design Units: Inch (Imperial)
• Lip Design: Springless Multi-Lip
• Durometer: 60–80 Shore A
• Operating Temperature Range: -40°F to 225°F (-40°C to 107°C)
• Weight: Approximately 0.105 lb (0.048 kg)
• Typical Applications: Industrial gearboxes, wheel hubs, axles, pumps, compressors, electric motors, agricultural equipment, and power transmission systems.

Common Replacements:

• SKF 18510 Oil Seal
• Federal-Mogul National 8521S
• Timken National 8521S Replacement Seal