Description
Brass Brake Adaptor 3/8″ UNF Male to M10 x 1 Female
Solid brass adaptor union with a 3/8″ x 24 UNF male end and an M10 x 1mm female end. Lets you run a metric M10 x 1 pipe union or hose into an imperial 3/8″ UNF port – ideal for mixing modern metric parts (calipers, hoses, kit-car components) with classic British imperial brake systems. Supplied by EMS Spares, Leicester.
Specification
| Male end | 3/8″ x 24 UNF |
|---|---|
| Female end | M10 x 1mm |
| Type | Brass adaptor union (imperial to metric) |
| Hex / spanner size | N/A |
| Overall length | N/A |
| Material / finish | Solid brass, natural finish – rust resistant |
| Weight | 27.9g approx |
| Interchange reference | HU156* |
| EMS part number | EMS-A156 |
* 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: brake adaptors explained
What does this adaptor do?
An adaptor joins two different threads in a brake or clutch line – here 3/8″ UNF male to M10 x 1 female. Typical use: fitting a metric (M10 x 1) brake pipe union or hose into an imperial 3/8″ UNF master cylinder, T-piece or caliper port.
Identify both threads
| Thread | Outside diameter (male thread) | Threads | Typically found on |
|---|---|---|---|
| 3/8″ x 24 UNF | 9.5mm approx | 24 per inch | Most British classics: MG, Triumph, Mini, Austin, Morris, Land Rover Series, Jaguar, kit cars |
| 3/8″ x 20 BSF | 9.5mm approx | 20 per inch | Older British cars (often pre-1960s) |
| M10 x 1mm | 10mm approx | 1mm pitch (about 25 per inch) | Most European and later cars |
| 7/16″ x 20 UNF | 11.1mm approx | 20 per inch | British classics, Land Rover and commercial vehicles, often clutch and 1/4″ pipe circuits |
Tip: 3/8″ UNF and M10 x 1 look almost the same and will start to screw in, then bind. Never force a fitting – forcing the wrong thread damages the port. Measure the male thread diameter or use a thread gauge, or compare against your old part.
Male or female?
- Male end: thread on the outside – screws into a port.
- Female end: thread on the inside – takes a male union or male port.
How to fit – good practice
- Check both threads before fitting – compare with your old part or use a thread gauge.
- Start every thread by hand for several turns – it should turn freely. If it binds, stop and check.
- Tighten with correctly sized split (flare nut) spanners. Hold the mating part with a second spanner so pipes do not twist. Brass is softer than steel – firm, not excessive.
- Bleed the system, then check every joint for leaks with the pedal pressed hard.
Safety: brakes and clutches are safety-critical systems. If you are not confident, have the work done or checked by a qualified mechanic.
Pack sizes
1, 3, 4 or 5 adaptors.
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
Why not just screw the M10 union in? 3/8″ UNF and M10 x 1 are close but not the same – forcing one into the other damages the threads and can leak. Always use an adaptor.
Need help? Message us with your vehicle and both threads.
Reviews
There are no reviews yet.