Stern bearing oil seals in marine propulsion prevent lubricant leakage from the stern tube while keeping seawater out. They ensure smooth operation of the propeller shaft by maintaining proper lubrication. These seals are critical for reducing friction, wear, and environmental contamination.

Size: Typically ranges from 50 mm to 500 mm inner diameter (ID), depending on shaft size.

Grade: High-performance marine-grade oil seals, often compliant with ISO 6194 or DIN 3760 standards.

Viscosity: Compatible with lubricants having viscosity grades ISO VG 68 to ISO VG 220.

Buoyancy: Designed to withstand underwater pressures, but not inherently buoyant.

Material: Nitrile rubber (NBR), polyacrylate (ACM), or fluorocarbon (FKM) for oil resistance; stainless steel or carbon steel for reinforcement.

Operating Temperature: -20°C to +120°C (-4°F to +248°F), depending on material.

Pressure Rating: Up to 0.5 MPa (5 bar) for standard designs.

Speed: Suitable for shaft speeds up to 15 m/s (49 ft/s).

Sealing Type: Lip seal with spring-loaded design for enhanced sealing efficiency.

Applications: Stern tube bearings, propeller shafts, and marine propulsion systems.

Stern Bearing Oil Seals and Marine Propulsion products typically comply with maritime standards such as ISO, ASTM, or specific classification society standards like ABS, DNV, or Lloyd's Register. For exact compliance, refer to the manufacturer's specifications or certification documents.