Piston Seal 45x57x6 K21 PU - Hydraulic Technical Seal

Applications of the 45x57x6 K21 PU Piston Seal

The 45x57x6 K21 PU piston seal is a high-performance technical seal designed for hydraulic and pneumatic systems operating under dynamic, reciprocating motion. Although often searched under terms such as oil seal, rotary shaft seal, or shaft sealing ring, this product is technically a piston seal, intended for linear movement rather than rotary applications.

The K21 profile is widely used in hydraulic cylinders, actuators, industrial machinery, construction equipment, and agricultural systems, where reliable sealing of hydraulic oil is required. Its geometry ensures stable sealing performance under pressure, making it suitable for demanding industrial applications where leakage control and efficiency are critical.

Advantages of the K21 PU Technical Seal

Manufactured from high-grade polyurethane (PU), the K21 piston seal offers high durability, excellent wear resistance, and outstanding mechanical strength compared to conventional rubber oil seals. PU material provides superior resistance to oils and grease, pressure fluctuations, and edge loading, ensuring long service life even in intensive operating conditions.

The optimized sealing lip design minimizes friction while maintaining effective sealing, reducing energy loss and extending component life. Unlike rotary shaft seals or engine seals, the K21 PU seal is specifically engineered for hydraulic seals in linear motion systems, where reliability and dimensional stability are essential.

Technical Data - 45x57x6 K21 PU

• Product type: Piston seal / hydraulic technical seal

• Profile: K21

• Material: Polyurethane PU

• Inner diameter: 45 mm

• Outer diameter: 57 mm

• Height: 6 mm

• Motion type: Reciprocating (linear)

• Media: Hydraulic oil

• Typical use: Hydraulic cylinders, industrial equipment

FAQ - Frequently Asked Questions

Is 45x57x6 K21 PU a rotary shaft seal?
No. Despite being searched as an oil seal or shaft seal, it is a piston seal designed for linear, not rotary, motion.

What are the benefits of PU over rubber seals?
Polyurethane offers higher wear resistance, better load capacity, and longer service life in hydraulic systems.

Can this seal be used in high-pressure applications?
Yes. The K21 profile is suitable for hydraulic systems operating under pressure.

Where is this seal commonly used?
In hydraulic cylinders, industrial machinery, and equipment requiring reliable piston sealing.