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

An ORFS bulkhead body one end and a UNO O-ring boss male the other. Passes through a panel and screws into a UNO port on an American-built pump or valve.

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

Watch: The Advantages of Hydraulic Bulkhead Fittings: Essential Components for Fluid Systems

Thread Standards

• ORFS Bulkhead Male – SAE J1453 O-ring face seal on a bulkhead body with a locknut. It seals on the O-ring in the flat face; the bulkhead thread and locknut only clamp the part to the panel.
• 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

• The bulkhead thread and locknut clamp the fitting to the panel. They do no sealing, so do not try to cure a leak by tightening the locknut.
• Check your panel hole size and thickness before you order. The body has a set thread length under the shoulder and a thick panel eats it.
• Both ends seal on an O-ring, one in a flat face and one against a port spotface. No sealant on either thread.
• Check the UNO port spotface for nicks before you fit. A scored face weeps past a good ring.

Technicians Advice

Seat the UNO end properly in its port first, ring just kissing the spotface then the specified turn. Then bring the body through the panel. Doing the locknut first leaves you no way to correct the UNO end.

Where You’ll Find It

• ORFS Bulkhead Male – panel and chassis pass-throughs on late-model machinery built on ORFS – excavators, loaders and truck-mounted equipment where vibration rules out thread-sealed joints.
• 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

• ORFS Bulkhead Male – SAE J1453 O-ring face seal, bulkhead style. Often written ORFS BH or O-ring face seal bulkhead. The face seal does the work, the locknut does not.
• 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)

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