AN6226-20 Buna-N 70 U-Cup Seal 1" ID X 1-1/2" OD X 1/4" CS

Made from black Buna-N (NBR) at 70 durometer, this U-Cup offers excellent oil resistance and reliable flexibility. It is a strong choice for customers who want a proven, cost-effective sealing solution that works across a wide range of hydraulic and pneumatic applications.

If you need a dependable hydraulic seal that installs easily and performs under pressure, the AN6226-20 U-Cup Seal is built for exactly that. Designed for low to moderate pressure systems, this seal delivers consistent sealing, reduces leakage, and helps keep your equipment running without interruption.

Operating temperature: -40° to +225°F (–40° to +107°C)

Material & Performance Details

This AN6226 U-Cup is manufactured from Buna-N (Nitrile, NBR), one of the most widely used sealing materials in the industry. With a 70 durometer hardness, it provides the right balance between flexibility for sealing and strength for durability.

These seals do not rely on initial compression, making them ideal for low breakaway pressure applications and smooth operation.

Excellent resistance to:

• Petroleum-based oils and fuels
• Hydraulic fluids
• Mineral oils and greases
• Water (short-term exposure)

Limited capability with:

• Mild acids and bases
• Outdoor ozone and weather exposure

Not compatible with:

• Strong acids
• Brake fluids (glycol-based)
• Aromatic hydrocarbons

Sizes & Measurements

• Dimensions: 1" ID X 1-1/2" OD X 1/4" CS
• Actual: 1.000" ID X 1.500" OD X 0.250" CS
• Metric: 25.40 mm ID X 38.10 mm OD X 6.35 mm CS
• Part Number: AN6226-20
• Cross References:
  • Parker Hannifin: 42956226-20
  • Hercules: 870-20
  • Martin Fluid Power: 6226-20
  • Precision Associates: 6226-20

Applications & Use Cases

AN6226 Series U-Cups are commonly used in hydraulic cylinders, pneumatic systems, pumps, and valves. They are especially effective in applications where low friction and reliable sealing are needed without excessive startup force.

You will find these seals in mobile equipment, industrial machinery, fluid power systems, and general repair applications where consistent performance matters.

Rated for pressures up to 500 PSI, this U-Cup provides dependable sealing without overdesigning your system.

Key Specifications

• Material: Buna-N (NBR)
• Durometer: 70 Shore A
• Color: Black
• Specification: AN6226 (Army-Navy Standard)
• Temperature Range: -40°F to +225°F (-40°C to +107°C)
• Pressure Rating: Up to 500 PSI

Why Buy from The O-Ring Store LLC

When you order from us, you are getting more than just a seal. You are getting accuracy, speed, and support that helps you get the job done right the first time.

• ISO9001:2015 certified quality processes
• USA-based inventory for fast delivery
• Same-day shipping on in-stock items
• Custom sizes available when standard does not fit
• Full lot traceability and documentation available
• Real technical support from experienced staff
• Competitive pricing without sacrificing quality

We make getting O-Rings easy, and that includes the seals that keep your systems running.

FAQs

1. What does AN6226 mean?
AN6226 is an Army-Navy specification that standardizes U-Cup seal dimensions and performance, ensuring interchangeability across manufacturers.

2. Can this seal be used in hydraulic oil systems?
Yes. Buna-N is highly resistant to petroleum-based oils and hydraulic fluids, making it ideal for hydraulic applications.

3. What pressure can this U-Cup handle?
This seal is rated for applications up to 500 PSI, suitable for many standard hydraulic and pneumatic systems.