AN6226-52 Buna-N 70 U-Cup Seal 1-1/8" ID X 1-1/2" OD X 3/16" CS

Get a reliable, low-friction seal that keeps your system running smooth and leak-free. The AN6226-52 U-Cup Seal is designed to deliver consistent sealing performance, helping reduce downtime and improve efficiency in hydraulic and pneumatic systems.

Manufactured from black Buna-N (NBR) at 70 durometer, this U-Cup provides excellent oil resistance and durability. The 3/16" square profile offers a strong balance of flexibility and sealing strength, making it a dependable choice for a wide range of fluid power applications.

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

Material & Performance Details

This AN6226 style U-Cup features a square profile where the nominal cross section equals the height. Originally designed for early aircraft applications, this profile is still widely used today due to its low friction performance and reliable sealing.

Manufactured from Buna-N (Nitrile, NBR) at 70 durometer, it provides a proven balance of flexibility, durability, and oil resistance.

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
• Ozone and outdoor exposure

Not compatible with:

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

Sizes & Measurements

• Cross Section (CS): 3/16" (0.187" | 4.75 mm)
• Inside Diameter (ID): 1-1/8" (1.125" | 28.58 mm)
• Outside Diameter (OD): 1-1/2" (1.500" | 38.10 mm)
• Part Number: AN6226-52
• Cross References:
  • Parker Hannifin: 42956226-52
  • Hercules: 870-52
  • Martin Fluid Power: 6226-52
  • Precision Associates: 6226-52

Dimensions: 1-1/8" ID X 1-1/2" OD X 3/16" CS
Actual: 1.125" ID X 1.500" OD X 0.187" CS
Metric: 28.58 mm ID X 38.10 mm OD X 4.75 mm CS

Applications & Use Cases

This AN6226 Series U-Cup is commonly used in hydraulic cylinders, pneumatic systems, pumps, and valves. Its low friction design makes it especially useful in applications requiring smooth movement and reliable sealing.

With a pressure rating up to 500 PSI, it is well suited for both OEM equipment and maintenance applications, including legacy systems that use AN-standard seals.

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 avoid downtime and rework.

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

We focus on helping you get the right seal the first time so your equipment keeps running.

FAQs

1. What makes the AN6226 square profile unique?
The square profile provides added stability and consistent sealing while maintaining low friction during operation.

2. Is Buna-N suitable for hydraulic systems?
Yes. Buna-N offers excellent resistance to petroleum-based oils and hydraulic fluids.

3. What pressure can this seal handle?
This U-Cup is rated for applications up to 500 PSI.