BSP Tapered Male x SAE O-Ring Boss Male 90° Compact Elbow

BSPT into the local port, O-ring boss male into an American pump or valve, turned hard at 90°. The crossover you hit whenever US-built hydraulics land on Australian plumbing and the hose has to double straight back.

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 Tapered Male – BSPT to ISO 7 / BS 21. It seals on the tapered thread itself, so it needs PTFE tape or a liquid thread sealant.
• 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 ORB end needs a machined boss with a spotface. It will not seal in a tapered port however hard you wind it.
• BSPT and NPT look alike. BSPT is 55°, NPT is 60°, and mixing them gives a joint that starts sweet and weeps forever.
• Take the O-ring size from the port. Boss O-rings are consumable and are often missing off a used fitting.

Technicians Advice

Wind the ORB end in until the O-ring just kisses the spotface, then nip it by feel. Overtightening squeezes the O-ring into the thread and it will seep inside a shift. The BSPT end is the opposite - it wants tape or sealant and real torque, because it seals on the thread.

Where You’ll Find It

• BSP Tapered Male – Older Australian and British pipework, gauge ports, tank and return lines, and cast pump and gearbox housings.
• 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 Tapered Male – BSPT to ISO 7 / BS 21, written R for male. Sometimes labelled PT or BSP taper.
• 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	H	S1	Material	Finish
BTM-UNM-90C-0407	1/4" BSPT	7/16" UNO	14.3mm	14mm	Mild steel	Plated finish
BTM-UNM-90C-0409	1/4" BSPT	9/16" UNO	17.5mm	14mm	Mild steel	Plated finish
BTM-UNM-90C-0412	1/4" BSPT	3/4" UNO	22.2mm	19mm	Mild steel	Plated finish
BTM-UNM-90C-0609	3/8" BSPT	9/16" UNO	17.5mm	16mm	Mild steel	Plated finish
BTM-UNM-90C-0612	3/8" BSPT	3/4" UNO	22.2mm	19mm	Mild steel	Plated finish
BTM-UNM-90C-0614	3/8" BSPT	7/8" UNO	25.4mm	22mm	Mild steel	Plated finish
BTM-UNM-90C-0812	1/2" BSPT	3/4" UNO	22.2mm	22mm	Mild steel	Plated finish
BTM-UNM-90C-0814	1/2" BSPT	7/8" UNO	25.4mm	22mm	Mild steel	Plated finish
BTM-UNM-90C-0817	1/2" BSPT	1.1/16" UNO	31.8mm	27mm	Mild steel	Plated finish
BTM-UNM-90C-1214	3/4" BSPT	7/8" UNO	25.4mm	27mm	Mild steel	Plated finish
BTM-UNM-90C-1217	3/4" BSPT	1.1/16" UNO	31.8mm	27mm	Mild steel	Plated finish
BTM-UNM-90C-1617	1" BSPT	1.1/16" UNO	31.8mm	33mm	Mild steel	Plated finish
BTM-UNM-90C-1621	1" BSPT	1.5/16" UNO	38.1mm	33mm	Mild steel	Plated finish
BTM-UNM-90C-1626	1" BSPT	1.5/16" UNO	47.6mm	41mm	Mild steel	Plated finish

Key: H centre to face, S1 hex across flats 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

🔗 Straight – same threads🔗 45° Compact – same threads

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Need a hand? Call 1300 146 737 or email sales@mhfgc.com.au – real technicians, real answers.