Description
Brass Brake Pipe Union 7/16″ UNF x 20 Male for 3/16″ Pipe
Solid brass male brake pipe union (male tube nut) with a 7/16″ x 20 UNF thread, made for 3/16″ (4.75mm) brake and clutch pipe. Used on British classic cars, Land Rover and commercial vehicles – commonly on master cylinder outlets, clutch circuits and 7/16″ UNF ports. Supplied by EMS Spares, Leicester – over 30 years in automotive components.
Specification
| Thread | 7/16″ x 20 UNF male (20 threads per inch) |
|---|---|
| Pipe size | 3/16″ (4.75mm) brake / clutch pipe |
| Type | Male union |
| Hex / spanner size | N/A |
| Overall length | N/A |
| Flare type | N/A |
| Material / finish | Solid brass, natural finish – rust resistant, will not seize |
| Weight | 12.2g approx each |
| Interchange reference | HU7* |
| EMS part number | EMS-A7 |
* Reference numbers are for identification only. All dimensions are approximate.
Buyer’s guide: 7/16″ UNF brake pipe unions explained
What does a brake pipe union do?
A brake pipe union is the threaded nut that holds a flared brake pipe tight against a component. The union itself does not seal; it clamps the flare on the end of the pipe into the seat, and that metal-to-metal contact makes the seal.
Step 1 – identify your thread
| Thread | Outside diameter (male thread) | Threads | Typically found on |
|---|---|---|---|
| 7/16″ x 20 UNF (this part) | 11.1mm approx | 20 per inch | British classics, Land Rover and commercial vehicles – often master cylinders, clutch circuits and 1/4″ pipe |
| 3/8″ x 24 UNF | 9.5mm approx | 24 per inch | Most British classic car brake circuits on 3/16″ pipe |
| 7/16″ x 24 UNF | 11.1mm approx | 24 per inch | Some older British vehicles – same diameter, finer thread |
| M12 x 1mm | 12mm approx | 1mm pitch | Many European cars, often on 1/4″ pipe |
Tip: 7/16″ x 20 and 7/16″ x 24 have the same diameter but different threads – count the threads per inch with a thread gauge or compare with your old part. Never force a union.
Step 2 – male or female?
- Male union (this part): thread on the outside – screws into a threaded port (master cylinder, wheel cylinder, T-piece).
- Female union: thread on the inside – screws onto a male port, such as many flexible hoses.
Step 3 – pipe size: 3/16″ or 1/4″?
This union is for 3/16″ (4.75mm) outside-diameter pipe. 7/16″ UNF unions come in two bore sizes: 3/16″ (4.75mm) – the standard car brake pipe – and 1/4″ (6.35mm) – used on many clutch circuits, master cylinder outlets and larger vehicles. Measure your pipe before ordering. For 1/4″ pipe choose EMS-A14.
How to fit – good practice
- Slide the union onto the pipe the right way round before you make the flare.
- Make the flare with a proper flaring tool, matching the flare of your old pipe and the component.
- Start the union by hand for several turns – it should turn freely. If it binds, stop and check the thread.
- Tighten with a correctly sized split (flare nut) spanner. 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
Available as 1, 2, 3 or 6 unions. Larger packs cost less per union.
Delivery
Free UK delivery on every order (including Northern Ireland, Highlands & Islands). Same-day dispatch on orders placed before 10am.
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FAQ
Will this fit copper (Kunifer) pipe? Yes – any 3/16″ (4.75mm) brake pipe: copper-nickel, copper or steel.
Is 7/16″ x 20 the same as 7/16″ x 24? No. Same diameter, different thread. Check your old union or port before ordering.
Need help? Message us with your vehicle and the part you are connecting to and we will confirm the right union before you order.




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