UNO O-Ring Boss Male x UNO O-Ring Boss Male Straight Adaptor

SAE O-ring boss both ends. Joins two UNO ports or extends a UNO connection, most often seen on American-built pumps, motors and valve banks.

Brand: Ayrtec – mild steel body with a plated finish, manufactured to the standards listed below.

Watch: 90 ° Hydraulic Adaptors How They Work and the Importance of O'Rings

Thread Standards

• SAE O-Ring Boss Male (UNO/UNF) – SAE J1926 / ISO 11926 straight thread O-ring boss. It seals on an O-ring squeezed against the port spotface, not on the thread.

How to Choose

• Both ends seal on an O-ring against the port spotface. Nothing goes on either thread.
• UNO and UNF share the same thread callouts. Go by the full callout, for example 7/8-14, not the fraction on its own.
• Check both port faces for nicks and burrs. A scored spotface weeps past a perfectly good ring.

Technicians Advice

Oil both O-rings before they go over the threads. Dragging a dry ring across a straight thread nicks the edge, and a nicked ring seals well enough to pass a test then seeps once the machine warms up and the oil thins.

Where You’ll Find It

• SAE O-Ring Boss Male (UNO/UNF) – Cylinder end caps, pump and valve bosses on US-built plant. Common on Australian-assembled cylinders too, where it is usually called UNO.

Cross-Reference

• SAE O-Ring Boss Male (UNO/UNF) – SAE J1926 / ISO 11926 straight thread O-ring boss. Also written ORB, SAE ORB or UNO. Thread form is UN/UNF.

Parker, Gates, Aeroquip and Ryco all manufacture to these same standards under their own part numbering, so a fitting built to the standard above will mate with theirs.

Cross-references are given at series level as a guide to the standard, not as a part-for-part substitution. Always confirm the thread form, size and seal type against the port before ordering.

Downloads

📄 Thread Identification Chart (PDF)

Same Threads, Other Angles

🔗 90° Compact – same threads

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