Whitworth (UNF) Fittings
Nipples, tees, reverse connectors, elbows and plugs.
16 products · 173 variants
What are whitworth (unf) fittings?
Whitworth (UNF / JIC 37°) fittings combine an inch-based UNF thread with a 60° thread angle and a 37° flare sealing face. The seal is metal-to-metal on the flare cone, not on the thread, so no gasket is needed and the joint stays reliable on lines that are opened frequently. It is common on construction machinery and American-built equipment.
BSP - UNF Connection Nipple
Nipple transitioning from BSP pipe thread to UNF (Whitworth).
Details & Table → UNF - UNF Connection Nipple
Equal-size nipple joining two UNF (Whitworth) threads.
Details & Table →
BSP - UNF Reverse Nipple
Reverse nipple from BSP pipe thread to UNF.
Details & Table →
UNF Weld-on Nipple
Weld-on UNF (Whitworth) threaded nipple.
Details & Table → Metric - UNF Connection Nipple
Nipple transitioning from metric thread to UNF (Whitworth).
Details & Table →
UNF Tee
Three-way UNF (Whitworth) tee fitting.
Details & Table →
UNF Branch Tee
Side-branch UNF (Whitworth) tee fitting.
Details & Table → UNF Run Tee
Center-branch UNF (Whitworth) tee fitting.
Details & Table → UNF Reverse Elbow
90° UNF (Whitworth) reverse (female) elbow.
Details & Table → UNF - UNF Reverse 45°
45° UNF-UNF reverse fitting.
Details & Table →
UNF - UNF Locknut 45°
45° UNF-UNF locknut (adjustable) fitting.
Details & Table →
NPT - UNF Male Threaded Elbow
90° male threaded elbow from NPT/pipe thread to UNF.
Details & Table →
UNF Threaded Elbow
90° UNF (Whitworth) male threaded elbow.
Details & Table →
UNF Male Blind Plug
Male blind plug for closing unused UNF female ports.
Details & Table → UNF Blind Nut Cap
UNF female (nut) blind cap closing a line end.
Details & Table →
UNF Bulkhead Nipple
UNF (Whitworth)-thread bulkhead pass-through nipple.
Details & Table →What to look for
- Flare angle
- JIC 37° and SAE 45° flares look almost identical but are not compatible. The wrong angle gives line contact and the joint starts weeping under vibration.
- Thread size
- UNF threads are named by diameter and pitch — 7/16-20, 9/16-18, 3/4-16. Always state both when ordering.
- Tightening torque
- With metal-to-metal sealing, over-tightening crushes the flare and creates a permanent leak. Follow the catalogue torque; if it leaks, inspect the face rather than tightening further.
- Adapters
- BSP-to-UNF, metric-to-UNF and NPT-to-UNF adapter nipples are used to join equipment built to different standards.
Frequently asked
How do I tell JIC 37° from SAE 45°?
Check the flare face with an angle gauge. They are hard to distinguish by eye; if in doubt refer to the equipment label or the original part number. Mismatching them is the most common cause of leaks.
Should a gasket be used on a UNF joint?
No. The seal comes from contact between the 37° flare faces. Adding a washer or tape breaks that contact and makes leakage worse.
Are Whitworth and UNF the same thing?
In the trade both names are often used for the same product group. The fittings listed here under Whitworth are JIC-type connections with 60° UNF threads and 37° flare sealing.