Rotary Shaft Seal 25x40x7 NBR SC - Single Lip Oil Seal

Applications

The Rotary Shaft Seal 25x40x7 NBR SC is a single lip oil seal designed for radial sealing of rotating shafts in non-pressurized industrial and automotive applications. It is commonly used in gearboxes, electric motors, pumps, small engines, and general machinery where reliable shaft sealing against oil or grease leakage is required. The SC profile is suitable for clean operating environments and standard housing designs.

Advantages

Manufactured from NBR (nitrile butadiene rubber), this rotary shaft seal offers excellent resistance to oils and grease, good elasticity, and stable performance over extended service life. The single sealing lip ensures consistent contact with the shaft surface, providing effective sealing while maintaining low friction and reduced wear. The reinforced outer diameter supports secure installation and dimensional stability in the housing bore, contributing to high durability in continuous operation.

Technical Data

• Product type: rotary shaft seal / oil seal

• Profile: SC (single lip)

• Inner diameter: 25 mm

• Outer diameter: 40 mm

• Width: 7 mm

• Material: NBR

• Design: single lip oil seal

• Operating mode: radial, non-pressurized rotary sealing

Main Description

The Rotary Shaft Seal 25x40x7 NBR SC is a versatile technical seal developed for standard rotary sealing tasks in industrial and automotive systems. As a single lip oil seal, it is optimized for applications where sealing efficiency, low friction, and long service life are more important than dust exclusion or pressure resistance.

The NBR compound provides reliable performance when exposed to mineral oils, greases, and common lubricants, making this seal suitable for hydraulic and automotive seals used in everyday machinery. The SC design focuses on simplicity and reliability, reducing installation complexity and minimizing the risk of premature wear. Compact dimensions allow installation in space-restricted housings, making it a practical choice for both OEM production and maintenance replacement.

For applications involving contamination, pressure, or aggressive environments, a double lip oil seal (TC) or alternative sealing solution may be recommended. In non-pressurized conditions, the SC profile delivers consistent and economical sealing performance.

FAQ - Frequently Asked Questions

What is the difference between a single lip and double lip oil seal?
A single lip oil seal provides primary sealing against oil, while a double lip seal adds a dust lip for contamination protection.

Is NBR suitable for oil sealing?
Yes, NBR offers very good resistance to mineral oils and greases commonly used in industrial equipment.

Can this seal operate under pressure?
No, SC seals are intended for non-pressurized applications.

How do I select the correct shaft seal size?
Match the inner diameter to the shaft, the outer diameter to the housing bore, and the width to the available groove depth.