Custom Plumbing Thread Adapters — Male to Female

When the Pipe Adapter Isn't on Any Shelf

Standard plumbing adapters cover the common sizes. The one you actually need is often the one no merchant stocks: an imported BSP port that has to meet an American NPT line, an odd reducer, an oversized fitting, or a thread on an old appliance no one makes anymore. You know exactly what should connect — you just can't buy the piece that joins it.

EKINSUN machines that piece. We make custom plumbing thread adapters, male to female, in any size and reducer combination, in lead-free brass for potable water or 316 stainless for corrosive lines — single pieces through small production, with a quote in 12 hours.

Need a higher-pressure hydraulic build instead? See hydraulic adapters. Pure thread-standard conversion across all engineering threads? See thread adapters.

BSP ↔ NPT, Male to Female — and Everything Between

The conversions and forms plumbers, installers and OEMs ask us for most:

Conversion / form	Typical use
BSP ↔ NPT	British pipe thread (BSPP/BSPT) to American NPT on imported pumps, valves, heaters and machinery
Male ↔ female	Any gender on each end — male-to-female, female-to-female, male-to-male
Reducers & odd sizes	Step a 1" down to 3/4", or oversized/fractional sizes no catalogue carries
Old / obsolete threads	Legacy imperial and discontinued plumbing threads reproduced from a sample

BSP and NPT don't simply screw together — BSPP is parallel and seals on a washer or O-ring face, while NPT (and BSPT) is tapered and seals on the thread. We machine the correct sealing feature on each end so the joint actually seals, instead of forcing a leak-prone mismatch.

Build Your Adapter Spec — Instant RFQ

Configure your plumbing adapter below. It generates clean RFQ text you can copy, or send straight to our engineers — no account, no CAD file.

Materials for Plumbing Adapters

No Drawing? We Reverse Engineer It

What to Send Us

• The sample fitting, or both parts it must connect — or photos with one known dimension
• The thread on each end if you know it (e.g. 1" BSP male to 3/4" NPT female)
• Medium (drinking water, hot water, gas, chemical) and pressure
• Whether the line needs lead-free / potable-safe material
• Quantity — one to prove the fit, or a batch — and delivery country

Where the Plumbing Catalogue Stops

BSP and NPT adapters in common sizes are on every merchant's shelf. These are the ones that are not.

What you need	In the catalogue?	How we machine it
A common BSP or NPT adapter, standard size	Stocked	Buy it off the shelf — a plumbing merchant will be cheaper and faster.
An oversized or fractional size no merchant carries	No	Stepping a 1″ down to an odd intermediate rather than the next stock size.
A legacy or discontinued plumbing thread	No	Reproduced from the sample you send, not from a chart.
Male-to-male or female-to-female across two standards	Thin	Any gender on each end, both cut on one body.
A longer or shorter body than the stock part	No	Cut to the space you have.
A seal face or O-ring groove added	No	For where thread sealant alone is not acceptable.
Left-hand thread on either end	No	Not stocked in any plumbing size.

Conversions above are the ones already listed on this page.

Frequently Asked Questions