UNO O-Ring Boss Male Blanking Plug

A UNO O-ring boss male plug for blanking an unused SAE port on an American-built pump, motor or valve bank.

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

Watch: Why You Need JIC Plugs Caps & O Ring Kit When Doing Hydraulic Repairs

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

• A plug is male and blocks a female port. A cap is female and covers a male end. Work out which one the open connection is before you order.
• Seals on the O-ring against the port spotface, never on the thread. No tape.
• Check the spotface is clean and unmarked before you fit it.

Technicians Advice

Oil the ring and ease it over the thread rather than dragging it in dry. Wind it until the ring just kisses the spotface then take it the specified turn. Past that the ring extrudes and the plug weeps.

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.

📐Dimensions & thread sizes – every size in this range

← Swipe the table sideways to see every measurement →

Part code	A	L	H1	Material	Finish
UNM-06	3/8" UNO	15mm	12.7mm	Mild steel	Plated finish
UNM-07	7/16" UNO	16mm	14.3mm	Mild steel	Plated finish
UNM-08	1/2" UNO	16mm	15.8mm	Mild steel	Plated finish
UNM-09	9/16" UNO	18mm	17.5mm	Mild steel	Plated finish
UNM-12	3/4" UNO	20mm	22.2mm	Mild steel	Plated finish
UNM-14	7/8" UNO	23mm	25.4mm	Mild steel	Plated finish
UNM-17	1.1/16" UNO	27mm	28.6mm	Mild steel	Plated finish
UNM-19	1.3/16" UNO	27mm	34.9mm	Mild steel	Plated finish
UNM-21	1.5/16" UNO	28mm	38.1mm	Mild steel	Plated finish
UNM-26	1.5/8" UNO	30mm	47.6mm	Mild steel	Plated finish
UNM-30	1.7/8" UNO	30mm	54.0mm	Mild steel	Plated finish
UNM-40	2.1/2" UNO	32mm	69.9mm	Mild steel	Plated finish

Key: L overall length, H1 centre to face 2. Measurements in millimetres unless shown otherwise. Thread columns show what each end mates with. Dimensions are nominal – check critical clearances against the part.

Downloads

📄 Thread Identification Chart (PDF)

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