Hex Nipple BSPT 3/8" x 3/8" - Tefen

Double male nipple 3/8" × 3/8" BSPT

Straight double male fitting with 3/8" BSPT threads on both sides and a central hex flat. It joins two 3/8" female ports end to end. Tefen range, reference TE-12012206068.

It is a simple but structural part: it extends a thread, joins two female components, or bridges a gap between two elements that cannot be screwed directly into each other.

The central hex

The hex flat in the middle of the body is not a styling detail.

On a plain or knurled nipple, tightening is done by hand or with pliers, with the risk of crushing or marking the body, especially on a polymer fitting. The hex gives a firm spanner grip, which applies torque where it belongs: on the fitting body, not on its threads.

That matters all the more on a tapered thread, where final tightening calls for controlled but real torque.

BSPT: a tapered thread

BSPT (British Standard Pipe Taper, ISO 7/1) is a tapered thread. Unlike a parallel thread that seals on a flat face or a gasket, BSPT seals on the threads themselves: the taper wedges into the port and tightening creates the contact.

Two practical consequences.

Sealant is always required, PTFE tape or pipe sealant, applied in the direction of tightening.

And do not overtighten. The taper acts as a wedge: on a polymer port, excessive tightening splits the receiving part. Hand-tight, then a quarter to a half turn with a spanner, bearing on the hex.

Do not confuse with NPTF. BSPT is the European standard, NPTF the American one. Both are tapered, but thread angle and pitch differ, 55° against 60°. They are not interchangeable: a BSPT male in an NPTF port engages only a few threads and will eventually leak. Always check the standard of both receiving ports before ordering.

Tefen polypropylene

Tefen fittings are made of polypropylene, a chemically inert material tolerating a wide pH range.

Against brass it has two clear advantages: it does not corrode, no dezincification, no threads seizing over time, and it is light, which reduces mechanical stress on the components it joins.

In exchange, it does not forgive over-tightening: where a brass nipple takes it, a polymer body splits. That is the only real assembly precaution.

Where to use it

On water treatment installations, irrigation, dosing circuits and process applications where chemical inertness matters more than mechanical strength. To join two components with 3/8" BSP female ports: valves, filters, pump bodies, tanks, manifolds.

Fitting

Apply PTFE in the direction of tightening, on both ends. Screw in by hand until it bottoms, then finish with a spanner on the hex, a quarter to a half turn.

Never tighten by gripping anything other than the hex, a grip on the thread damages it and compromises the seal permanently.