Two Threads, One Part — That Nobody Stocks
Standard adapters exist for standard pairs. The trouble starts the moment your two threads aren't a stocked pair: a metric sensor into an imperial port, a BSP tap into NPT plumbing, a vintage fuel fitting into a modern line, a gauge with a thread no current catalog lists. Suddenly there is no part number to buy.
That's a machining job, not a shopping problem — and it's a perfect fit for a hand drawing. An adapter is a short bar with a thread on each end. Tell us the two threads and the body, and we redraw it in CAD for free, confirm the threads, and turn it on our lathes. One piece or a batch.
What to Put on Your Sketch
An adapter is defined by its two ends and the body between them:
- Thread size (e.g. M30, 1/2")
- Pitch / TPI (e.g. ×3.5, 14 TPI)
- Male or female
- Thread size (e.g. M24, 3/8" NPT)
- Pitch / TPI
- Male or female
Then the body — hex (so it can be wrenched) or round, and rough overall length — plus the material and whether it has to seal pressure. Don't have every number? Send what you have, or send the two parts it bolts between, and we fill in the rest.
Not Sure What Thread You Have?
Identifying the thread is the one step that matters most — get it right and the rest is easy. You have three options, easiest last:
- Measure it. Caliper the outside diameter of a male thread (or the inside diameter of a female), then count threads per inch or measure the distance between two crests for the pitch. Send us those two numbers.
- Photograph it next to a ruler and tell us what it screws into. Often that's enough for us to recognise the standard.
- Send us the part. If it's loose, mail us the fitting (or the mating part) and we'll identify the thread on our end and machine the adapter to match — guaranteed fit.
We confirm the thread before we cut. Every adapter order is checked against thread gauges, and we flag anything ambiguous with a specific question. You approve the CAD before a single piece of metal is touched.
Adapters We Make From a Sketch
Reducers & step adapters
Large thread one end, smaller the other — the classic "step down" in any size combination.
Metric ↔ imperial
Join a metric thread to a UNF/UNC/BSW imperial thread in a single part — no double adapters.
BSP ↔ NPT & pipe threads
BSPP, BSPT, NPT, NPTF crossovers for plumbing, air and process lines.
Hydraulic & pneumatic
JIC 37°, ORFS, DIN tube fittings and gauge ports, with the correct sealing face.
Sensor & gauge adapters
Get an odd-thread sensor, transducer or gauge into a standard port.
Restoration & vintage
Obsolete or whitworth-era threads matched so old equipment takes modern fittings.
Materials & Sealing
| Material | Best for | Notes |
|---|---|---|
| Brass | Plumbing, air, fuel, gauges | Easy to seal, corrosion-resistant, great machinability |
| Stainless 316 / 303 | Hydraulic, marine, chemical, food | 316 for saltwater and aggressive media |
| Carbon / alloy steel | High-pressure hydraulics | Zinc-plated for corrosion resistance |
| Aluminum | Lightweight, low-pressure, cosmetic | Anodizable; not for high-pressure threads |
For sealing we machine the right face for the job — tapered threads (NPT/BSPT) that seal on the thread, or a flat or cone face for an O-ring or bonded washer. Tell us the pressure and medium and we'll specify it with your quote.
Catalog has the threads but never together? That's exactly the gap we fill. Off-the-shelf adapters cover common pairs; we machine the pair that doesn't exist — from your drawing, in any quantity from one piece.
Real Job: M30×3.5 → M24×2 Reducer From a Hand Sketch
A French client needed a one-off reducer — M30×3.5 female on one face, M24×2 male on the other, in a 50 mm hex body — a combination no catalog stocks. He sent a hand sketch; we returned a full 3D model the same day, raised the three dimensions that needed confirming, and quoted it for machining in steel or stainless. No CAD file from the customer.
Read the full thread-adapter case study →
Frequently Asked Questions
Yes. Sketch the two ends — size, pitch and male/female on each — plus the body and material. We redraw it as CAD for free, confirm the threads against gauges, and machine it. No CAD software needed on your side.
Yes. Measure the diameter and pitch/TPI and send us those, or simply send the part (or its mating part) and we identify the thread on our end. We confirm it before machining so the fit is guaranteed.
Yes — that's the most common reason for a custom adapter. Metric to imperial, BSP to NPT, JIC to ORFS, tube fitting to gauge port. Any two threads in one machined body.
Tell us the pressure and medium and we machine the correct sealing face — tapered threads for a thread seal, or a flat/cone face for an O-ring or bonded washer. We make adapters for hydraulic, pneumatic, fuel, water and gauge lines.
Yes, MOQ is 1 piece with no setup fee. Order one to confirm the fit, then reorder a batch at a lower unit price — we keep your CAD on file.
Related: all hand-drawing & sketch machining · spacers & bushings from a sketch · knobs from a sketch · adapters & fittings catalog · order with no CAD · CNC turning
Get a Free Quote
Send both threads (size + pitch + male/female) — or a sketch. We reply within 24 hours.
// Qty & price
1 pc
Sample price
Confirm fit before a run
3–10
Unit price drops
Setup cost shared
10+
Best price
All tiers quoted upfront
- →No distributor — you pay the maker directly
- →CAD saved after first order — reorder anytime at lower unit price
Response within 24h · Drawings kept confidential