ORFS Male x UNO O-Ring Boss Male Straight Adaptor

O-ring face seal one end, SAE O-ring boss the other. Two soft-sealed ends on one part, which is the pairing most late-model American machinery is built around.

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

• ORFS Male – SAE J1453 O-ring face seal. It seals on an O-ring sitting in the flat face groove, never on the thread.
• 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

• Neither end seals on the thread. No tape, no sealant, on either side.
• The UNO end wants a clean port spotface. The ORFS end wants a clean face groove. Two things to look at, not one.
• Both ends carry different O-ring sizes. Keep the spares sorted rather than working out of one tin.

Technicians Advice

This is a good fitting to standardise on for high-vibration mounts, because there is nothing on it that can shake loose or fret. Just be aware that two soft seals means two things to check when something does weep, and the fix is almost never more torque.

Where You’ll Find It

• ORFS Male – High-pressure, high-vibration circuits on late-model excavators, drill rigs, crushers and forestry gear.
• 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 Male – SAE J1453 / ISO 8434-3 O-ring face seal. Parker call this series Seal-Lok. Also written ORFS or flat face.
• 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	B	L	H1	Material	Finish
ORM-UNM-0907	9/16" ORFS	7/16" UNO	29mm	15.9mm	Mild steel	Plated finish
ORM-UNM-0909	9/16" ORFS	9/16" UNO	31mm	19.0mm	Mild steel	Plated finish
ORM-UNM-1107	11/16" ORFS	7/16" UNO	34mm	19.0mm	Mild steel	Plated finish
ORM-UNM-1109	11/16" ORFS	9/16" UNO	32mm	19.0mm	Mild steel	Plated finish
ORM-UNM-1112	11/16" ORFS	3/4" UNO	35mm	22.2mm	Mild steel	Plated finish
ORM-UNM-1114	11/16" ORFS	7/8" UNO	37mm	27.0mm	Mild steel	Plated finish
ORM-UNM-1309	13/16" ORFS	9/16" UNO	37mm	22.2mm	Mild steel	Plated finish
ORM-UNM-1312	13/16" ORFS	3/4" UNO	37mm	22.2mm	Mild steel	Plated finish
ORM-UNM-1317	13/16" ORFS	1.1/16" UNO	44mm	31.8mm	Mild steel	Plated finish
ORM-UNM-1321	13/16" ORFS	1.5/16" UNO	46mm	38.1mm	Mild steel	Plated finish
ORM-UNM-1612	1" ORFS	3/4" UNO	45mm	27.0mm	Mild steel	Plated finish
ORM-UNM-1614	1" ORFS	7/8" UNO	43mm	27.0mm	Mild steel	Plated finish
ORM-UNM-1617	1" ORFS	1.1/16" UNO	47mm	31.8mm	Mild steel	Plated finish
ORM-UNM-1912	1.3/16" ORFS	3/4" UNO	49mm	31.8mm	Mild steel	Plated finish
ORM-UNM-1914	1.3/16" ORFS	7/8" UNO	51mm	31.8mm	Mild steel	Plated finish
ORM-UNM-1917	1.3/16" ORFS	1.1/16" UNO	49mm	31.8mm	Mild steel	Plated finish
ORM-UNM-1921	1.3/16" ORFS	1.5/16" UNO	50mm	38.1mm	Mild steel	Plated finish
ORM-UNM-2317	1.7/16" ORFS	1.1/16" UNO	54mm	38.1mm	Mild steel	Plated finish
ORM-UNM-2321	1.7/16" ORFS	1.5/16" UNO	50mm	38.1mm	Mild steel	Plated finish
ORM-UNM-2326	1.7/16" ORFS	1.5/8" UNO	52mm	47.6mm	Mild steel	Plated finish
ORM-UNM-2721	1.11/16" ORFS	1.5/16" UNO	52mm	44.5mm	Mild steel	Plated finish
ORM-UNM-2726	1.11/16" ORFS	1.5/8" UNO	52mm	47.6mm	Mild steel	Plated finish
ORM-UNM-2730	1.11/16" ORFS	1.7/8" UNO	54mm	54.0mm	Mild steel	Plated finish
ORM-UNM-3226	1.11/16" ORFS	1.5/8" UNO	52mm	47.6mm	Mild steel	Plated finish
ORM-UNM-3230	1.11/16" ORFS	1.7/8" UNO	54mm	54.0mm	Mild steel	Plated finish
ORM-UNM-0912	9/16" ORFS	3/4" UNO	35mm	22.2mm	Mild steel	Plated finish
ORM-UNM-1314	13/16" ORFS	7/8" UNO	40mm	27.0mm	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)

Same Threads, Other Angles

🔗 45° Compact – same threads🔗 90° Compact – same threads

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