// Custom Double-Male Thread Adapters

Custom Male-to-Male Thread Adapters

Double-male studs and nipples with a male thread on each end — joining or converting two male threads in any combination: metric, UNC/UNF, BSP, NPT. Same or different thread each end, machined to your two sizes.

Any two male threads — metric, UNF/UNC, BSP, NPT
Same or different pitch each end; left-hand on request
Brass / 303 / 316L / steel / titanium
MOQ 1, quote 24h

What a Male-to-Male Adapter Does

A male-to-male (double-male) adapter is a short machined stud with an external thread on both ends. It solves three jobs a catalog rarely covers at once: joining two female ports, extending a stud, or converting one male thread to a different male thread — for example bringing an M12×1.5 male end out to a 1/4" NPT male end. Because each end is turned independently, the two threads can be any combination you need.

This is a different form from a female-to-male reducer (which screws over a male thread) and from the general forms compared on our thread adapter types guide — start there if you are not sure which gender you need.

DOUBLE-MALE ADAPTER — MALE THREAD EACH END HEX END A — e.g. M12×1.5 END B — e.g. 1/4" NPT

Ends We Combine

Any two of these on one stud, parallel or tapered, coarse or fine, right- or left-hand:

Thread familyExamplesStandard referenced
MetricM6–M48, coarse & fine (M12×1.5, M20×1.5…)ISO 261 / ISO 68-1 / DIN 13
Unified inchUNC, UNF, UNEF — ¼"–2"ASME B1.1
BSP parallel (G)G1/8–G2, sealing on washer/O-ringISO 228-1 / BS EN ISO 228
BSP taper / NPTRc/R, 1/8–2" NPT, self-sealingISO 7-1 · ASME B1.20.1
WhitworthBSW/BSF for legacy machineryBS 84

Which Material? Cost, Corrosion & Sealing

An adapter's material sets its cost, corrosion resistance and how it seals and machines. Most go out in brass or stainless; the job decides:

MaterialDensityWhy choose it for an adapter
Brass (CZ121 / C360)8.5 g/cm³The default — free-machining, good sealing, low cost, non-sparking
Stainless 3037.9 g/cm³Free-machining stainless for general corrosion resistance
Stainless 316L8.0 g/cm³Marine, chemical and washdown; the workhorse for harsh media
Steel (zinc-plated)7.85 g/cm³High-pressure hydraulic strength at low cost
Aluminum 60612.70 g/cm³Light, for low-pressure and weight-sensitive use
Titanium Gr54.43 g/cm³Light, very strong and corrosion-proof — premium and aerospace

The Jobs That Land on Our Bench

// Instrumentation

"A pressure gauge has a G1/4 male stem — the port is M14×1.5 female. Nothing off-the-shelf fits."

A double-male adapter, G1/4 parallel one end, M14×1.5 the other, with a bonded-seal shoulder under the G end. Machined in brass or 316L, sealed to the pressure you specify.

// Machinery maintenance

"Need to join two rods that both have male ends — one M16, one 5/8 UNC."

A double-male stud with a wrenching hex in the middle, M16 one end, 5/8" UNC the other. We match the pitches exactly and gauge both threads before it ships.

// Fluid power

"1/4 NPT male to 1/8 BSPT male to bridge a US pump to a European manifold."

Tapered both ends for self-sealing, machined to ASME B1.20.1 and ISO 7-1 — one stud that joins two standards that were never meant to meet.

Not sure of the gender? If one side needs to screw over a male thread, you want a female-to-male adapter instead. Crossing metric and imperial? See metric-to-imperial adapters. Send us the two parts and we'll confirm the right form.

Frequently Asked Questions

A short machined stud with an external thread on each end — it joins two female ports, extends a stud, or converts one male thread to a different male thread. The two ends can be the same or completely different.

Yes — that's the point. Any two threads: metric to metric of a different pitch, metric to UNF, BSP to NPT, coarse to fine, or left-hand to right-hand. Each end is machined independently.

Related: a stud usually has the same thread each end for clamping; a male-to-male adapter converts or joins two different threads, often with a central hex. We machine both — see double-end studs.

Yes — a parallel thread seals on a bonded washer, O-ring or face; a tapered thread (NPT/BSPT) seals on the thread. We machine the right sealing form for each end.

The thread and pitch for each end, parallel or tapered, overall length, whether you need a hex, the material — or the two parts you're joining. Quote in 24 hours.

Two Male Threads That Won't Meet?

Any two ends — metric, UNF, BSP, NPT — on one machined stud, sealed for pressure if needed. Quote in 24 hours.

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