Description
Brass Adaptor M10 x 1mm Female to 1/8″ NPT Male
Solid brass thread adaptor with an M10 x 1mm female thread and a 1/8″ NPT male taper thread. Commonly used to fit oil or brake pressure gauges, senders and switches, or to connect an M10 x 1 male fitting to a 1/8″ NPT port. Supplied by EMS Spares, Leicester – over 30 years in automotive components.
Specification
| Thread A | M10 x 1mm female |
|---|---|
| Thread B | 1/8″ NPT male (taper) |
| Type | Thread adaptor / reducer |
| Hex / spanner size | N/A |
| Material / finish | Solid brass, natural finish – rust resistant, will not seize |
| Interchange reference | HU101* |
| EMS part number | EMS-A101 |
* Reference numbers are for identification and cross-reference only. EMS Spares is an independent UK supplier and has no connection with the owners of these part numbers. All dimensions are approximate.
Buyer’s guide: brass thread adaptors explained
What does a thread adaptor do?
A brake adaptor converts one thread to another, so a pipe, hose, switch or gauge with one thread can connect to a port with a different thread – for example when fitting a new master cylinder, valve or gauge.
Step 1 – identify your thread (the most common mistake)
| Thread | Outside diameter (male part) | Threads | Typically found on |
|---|---|---|---|
| M10 x 1mm (this part) | 10mm approx | 1mm pitch (about 25 per inch) | Most European and Japanese cars, many later British cars and kit cars |
| M10 x 1.25mm | 10mm approx | 1.25mm pitch | Some older Italian and French cars (e.g. Fiat, Lancia) |
| 3/8″ x 24 UNF | 9.5mm approx | 24 per inch | Most British classics: MG, Triumph, Mini, Land Rover Series |
| M12 x 1mm | 12mm approx | 1mm pitch | Larger ports, some master cylinders and 1/4″ pipe |
Tip: Adaptors have two different threads – check both. M10 x 1 and 3/8″ UNF look almost the same, and M12 x 1 can be confused with 1/2″ UNF. Measure each thread and check the pitch with a thread gauge.
Step 2 – NPT taper thread
1/8″ NPT is a tapered pipe thread that seals on the thread itself. Use a suitable thread sealant on the NPT end only (never on brake flare seats).
How to fit – good practice
- Identify both threads before you order – measure each one and check the pitch.
- Start each thread by hand for several turns – it should turn freely. If it binds, stop and check the thread.
- Hold the adaptor with one spanner while you tighten the mating part with another, so it does not twist.
- Bleed the system and check every joint for leaks.
Safety: brakes are a safety-critical system. If you are not confident, have the work done or checked by a qualified mechanic.
Pack sizes
Available as 1 or 2 adaptors. Larger packs cost less per piece.
Delivery
Free UK delivery on every order (including Northern Ireland, Highlands & Islands). Same-day dispatch on orders placed before 10am.
Trusted by thousands of buyers on eBay
99.9% positive feedback from over 9,700 ratings, and 5.0 out of 5 for accurate description, postage cost, delivery time and communication (last 12 months). Read our eBay feedback.
FAQ
Is 1/8″ NPT the same as 1/8″ BSP? No. NPT has 27 threads per inch and a 60 degree thread; BSP has 28 and 55 degrees. They are not interchangeable.
Can I use it for an oil pressure gauge? Yes, where the gauge or port needs M10 x 1 female to 1/8″ NPT male.
Need help? Message us with your vehicle and the part you are connecting to and we will confirm the right fitting before you order.



Reviews
There are no reviews yet.