Custom M16 to M12 Thread Adapter — Sensor Mounts, Mechanical Joints & Repair

Need an M16 to M12 adapter for a sensor or probe, a mechanical joint, or to repair a worn thread — in steel or stainless, at the right pitch? We machine it to order, including the non-standard pitches and reducing-insert forms a catalog won't carry. From a sketch, no CAD, one piece up. Get a quote →

Gland reducer, or a machined adapter?

"M16 to M12" turns up two very different parts. Most listings are cable gland reducers — thin brass or nylon with an O-ring, for stepping a cable entry down. That's the right part for an electrical gland. But if your M16/M12 joint holds a sensor, a fitting, or any load, or the pitch isn't the standard gland thread, you want a solid machined adapter. Here's the quick split:

Forms — including a thread repair insert

Because it's turned to order, the M16-to-M12 can be whatever your job needs:

• Male-female adapter — M16 male to M12 female (or reverse), to convert or extend a thread.
• Reducing insert (repair) — M16 male outside, M12 female inside; threads into a worn or oversized M16 hole and gives a fresh M12 thread.
• Double-male stud — M16 and M12 male, to join two female parts.
• Female-female coupling — to join two male threads.

Pitch & material options

Option	Choices	Notes
M16 end	M16×2.0 (coarse) · M16×1.5 (fine)	Male or female
M12 end	M12×1.75 (coarse) · M12×1.5 · M12×1.25 (fine)	Sensor threads vary — tell us
Form	Adapter · reducing insert · double-male · female-female	To suit the job
Material	Steel · stainless 304 / 316 · brass on request	Plated or passivated
Seal	Plain · O-ring groove · sealing face	If it must be leak-tight
Drive	Hex · spanner flats · knurl for hand-tight	To suit clearance

Typical uses

• Sensor & probe mounts — fit an M12 sensor, transducer or thermocouple into an M16 boss, or the reverse.
• Instrument & fitting adaptation — gauges, valves and small fittings that don't share a thread.
• Thread repair — recover a stripped or oversized M16 hole with an M12 insert instead of scrapping the part.
• Light mechanical joints — eye fittings, standoffs and brackets where the two threads differ.

Other size adapters we machine

Frequently asked

Is this the same as an M16 to M12 cable gland reducer?

No. Gland reducers are thin brass or nylon with an O-ring, for cable entries. We machine a solid steel or stainless M16-to-M12 adapter for sensor mounts, mechanical joints and repair, in the exact pitch and form you need. Only need a gland reducer? A catalog part is cheaper.

Can you make it as a reducing insert to repair a hole?

Yes — M16 male outside, M12 female inside, to recover a worn M16 hole with a fresh M12 thread. We also do male-female, double-male and female-female.

Which pitches can you cut?

M16×2.0 or ×1.5, and M12×1.75, ×1.5 or ×1.25, plus non-standard pitches. Each end is gauged. More on coarse vs fine pitch →

Can I mount an M12 sensor in an M16 boss with this?

Yes — one of the most common uses. We machine an M16-male to M12-female adapter with a hex and, if needed, a seal face. Tell us the sensor thread and whether it must be leak-tight. See sensor adapters →