Description

Brass Brake Pipe Union M10 x 1mm Male Short for 3/16″ Pipe

Solid brass male brake pipe union (male tube nut) with an M10 x 1mm external thread, short pattern (18mm approx), made for 3/16″ (4.75mm) brake and clutch pipe. For shallow M10 x 1 female ports – calipers, wheel cylinders, valves and T-pieces – where the long union is too long. Supplied by EMS Spares, Leicester – over 30 years in automotive components.

Specification

* 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 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 or hose. The union itself does not seal; it clamps the flare on the end of the pipe against the seat of the mating part, and that metal-to-metal contact makes the seal. That is why the thread and the flare type must both match.

Step 1 – identify your thread (the most common mistake)

Tip: M10 x 1 and 3/8″ UNF look almost the same and will start to screw together, then bind. M10 x 1 and M10 x 1.25 also look alike. Never force a fitting. Measure the male thread (10mm = M10, 9.5mm = 3/8″) and check the pitch with a thread gauge.

Step 2 – male or female?

• Male union (this part): thread on the outside – screws into a threaded hole (master cylinder, wheel cylinder, caliper, T-piece, brake valve).
• Female union: thread on the inside – screws onto a male port, such as the end of many flexible brake hoses. See our EMS-A2A female union.

Step 3 – short or long, pipe size and material

This is the short male union (18mm approx). If the port is deep, use the long version – see our EMS-A2 long male union (21mm approx). Compare with your old union before you order.

For 3/16″ (4.75mm) outside-diameter pipe, the standard UK car brake pipe size. Suits copper-nickel (Kunifer), copper and steel brake pipe. Match the flare on your pipe to the port it screws into – most metric ports take a DIN (inverted) or ISO bubble flare; if in doubt, copy the flare on your old pipe.

How to fit – good practice

1. Slide the union onto the pipe the right way round before you make the flare.
2. Make the flare with a proper flaring tool, matching the flare of your old pipe and the port it screws into.
3. Start the union by hand for several turns – it should turn freely. If it binds, stop and check the thread.
4. Tighten with an 11mm split / flare nut spanner, not an open-ended spanner, so the brass hex is not rounded.
5. Bleed the brakes, then check every joint for leaks with the pedal pressed hard.

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 3, 5, 10 or 20 unions. 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.

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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 M10 x 1 the same as 3/8″ UNF? No. They are close in size (10mm against 9.5mm) but the threads are different and will bind. They are not interchangeable.

Short or long – which do I need? Measure your old union. The short one is about 18mm overall, the long one (EMS-A2) about 21mm.

Why brass and not steel? Brass does not rust or seize, so the union can be undone again years later without twisting the pipe.

Which spanner do I need? The hex is 11mm A/F – an 11mm split (flare nut) spanner fits best.

Need help? Message us with your vehicle and the part you are connecting to and we will confirm the right fitting before you order.