AN6226-14 Buna-N 70 U-Cup Seal 5/8" ID X 1-1/8" OD X 1/4" CS

Made from black Buna-N (NBR) at 70 durometer, this U-Cup offers excellent oil resistance and durability. The square 1/4" cross section provides added sealing stability, making it a dependable choice for demanding applications.

Get a stable, reliable seal that performs under pressure and keeps your system leak-free. The AN6226-14 U-Cup Seal is designed to deliver consistent sealing, reduce downtime, and support smooth operation in hydraulic and pneumatic systems.

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

Material & Performance Details

This U-Cup is manufactured from Buna-N (Nitrile, NBR), a proven sealing material used across fluid power industries. The 70 durometer hardness provides a balanced combination of flexibility and long service life.

The AN6226 profile features a square-style cross section where the nominal cross section equals the height. This design improves sealing stability and provides consistent performance under pressure.

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): 1/4" (0.250" | 6.35 mm)
• Inside Diameter (ID): 5/8" (0.625" | 15.88 mm)
• Outside Diameter (OD): 1-1/8" (1.125" | 28.58 mm)
• Part Number: AN6226-14
• Cross References:
  • Parker Hannifin: 42956226-14
  • Hercules: 870-14
  • Martin Fluid Power: 6226-14
  • Precision Associates: 6226-14

Dimensions: 5/8" ID X 1-1/8" OD X 1/4" CS
Actual: 0.625" ID X 1.125" OD X 0.250" CS
Metric: 15.88 mm ID X 28.58 mm OD X 6.35 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 that require reliable sealing with low friction and consistent performance.

With a pressure rating up to 500 PSI, it is well suited for both OEM systems 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. What does AN6226 mean?
AN6226 is an Army-Navy specification that standardizes U-Cup seal dimensions and ensures interchangeability.

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.