AN6226-51 Buna-N 70 U-Cup Seal 1" ID X 1-3/8" OD X 3/16" CS

Get a reliable seal that delivers consistent performance without overdesigning your system. The AN6226-51 U-Cup Seal is built to prevent leaks, reduce downtime, and keep your hydraulic and pneumatic equipment running smoothly.

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

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

Material & Performance Details

This seal is made from Buna-N (Nitrile, NBR), a widely trusted material in fluid power systems. The 70 durometer hardness provides a strong balance between flexibility and durability.

The AN6226 design ensures reliable sealing with low breakaway friction, making it ideal for dynamic applications where smooth operation is important.

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" (1.000" | 25.40 mm)
• Outside Diameter (OD): 1-3/8" (1.375" | 34.93 mm)
• Part Number: AN6226-51
• Cross References:
  • Parker Hannifin: 42956226-51
  • Hercules: 870-51
  • Martin Fluid Power: 6226-51
  • Precision Associates: 6226-51

Dimensions: 1" ID X 1-3/8" OD X 3/16" CS
Actual: 1.000" ID X 1.375" OD X 0.187" CS
Metric: 25.40 mm ID X 34.93 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. It is ideal for applications requiring reliable sealing with low friction and consistent performance.

With a pressure rating up to 500 PSI, it is well suited for both OEM equipment and maintenance applications.

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. Why choose a 3/16" cross section?
It provides a strong balance between sealing strength and flexibility, making it suitable for a wide range of applications.

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.