BSP Parallel Male x SAE O-Ring Boss Male Straight Adaptor

BSPP into the local port, O-ring boss male into an American pump or valve. The straight crossover you reach for whenever US-built hydraulics land on Australian plumbing.

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

• BSP Parallel Male – BSPP to ISO 228. It seals on a bonded washer against the port face or on a 60° cone, never on the thread itself.
• 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

• Check the boss, not the hose. SAE ORB ports have a machined spotface and a lead-in chamfer; a plain tapped hole is not ORB.
• Two soft seals, no tape - a bonded washer at the BSPP end, an O-ring at the boss.
• Take the O-ring size from the port. Boss O-rings are consumable and often missing off a used fitting.

Technicians Advice

Wind the ORB end in until the O-ring just touches the spotface, then nip by feel. Overtightening extrudes it into the thread and it seeps within a shift. Neither end here wants heavy torque - both rely on a soft seal doing its job.

Where You’ll Find It

• BSP Parallel Male – Valve and manifold ports on Australian, British and Asian-built equipment, and most locally made hose ends. The default port thread on Australian truck and agricultural hydraulics.
• 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

• BSP Parallel Male – BSPP to ISO 228 / BS 2779, written G. Also called BSP parallel or gas thread.
• 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
BPM-UNM-0407	1/4" BSPP	7/16" UNO	29mm	19mm	Mild steel	Plated finish
BPM-UNM-0408	1/4" BSPP	1/2" UNO	29mm	19mm	Mild steel	Plated finish
BPM-UNM-0409	1/4" BSPP	9/16" UNO	29mm	19mm	Mild steel	Plated finish
BPM-UNM-0412	1/4" BSPP	3/4" UNO	31mm	22mm	Mild steel	Plated finish
BPM-UNM-0607	1/4" BSPP	7/16" UNO	29mm	19mm	Mild steel	Plated finish
BPM-UNM-0608	3/8" BSPP	1/2" UNO	29mm	19mm	Mild steel	Plated finish
BPM-UNM-0609	3/8" BSPP	9/16" UNO	31mm	19mm	Mild steel	Plated finish
BPM-UNM-0612	3/8" BSPP	3/4" UNO	33mm	22mm	Mild steel	Plated finish
BPM-UNM-0614	3/8" BSPP	7/8" UNO	37mm	27mm	Mild steel	Plated finish
BPM-UNM-0809	1/2" BSPP	9/16" UNO	35mm	27mm	Mild steel	Plated finish
BPM-UNM-0812	1/2" BSPP	3/4" UNO	37mm	27mm	Mild steel	Plated finish
BPM-UNM-0814	1/2" BSPP	7/8" UNO	39mm	27mm	Mild steel	Plated finish
BPM-UNM-0817	1/2" BSPP	1.1/16" UNO	41mm	32mm	Mild steel	Plated finish
BPM-UNM-1212	3/4" BSPP	3/4" UNO	38mm	32mm	Mild steel	Plated finish
BPM-UNM-1214	3/4" BSPP	7/8" UNO	39mm	32mm	Mild steel	Plated finish
BPM-UNM-1217	3/4" BSPP	1.1/16" UNO	41mm	32mm	Mild steel	Plated finish
BPM-UNM-1219	3/4" BSPP	1.3/16" UNO	43mm	36mm	Mild steel	Plated finish
BPM-UNM-1221	3/4" BSPP	1.5/16" UNO	45mm	38mm	Mild steel	Plated finish
BPM-UNM-1617	1" BSPP	1.1/16" UNO	46mm	41mm	Mild steel	Plated finish
BPM-UNM-1619	1 BSPP	1.3/16" UNO	48mm	41mm	Mild steel	Plated finish
BPM-UNM-1621	1" BSPP	1.5/16" UNO	48mm	41mm	Mild steel	Plated finish
BPM-UNM-1626	1" BSPP	1.5/8" UNO	50mm	50mm	Mild steel	Plated finish
BPM-UNM-2026	1.1/4" BSPP	1.5/8" UNO	50mm	50mm	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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