Description
Brass Bulkhead Brake Union 3/8″ UNF x 24 with Brass Half Nut
Solid brass bulkhead brake union with 3/8″ x 24 UNF male threads at both ends, supplied with a brass half nut (lock nut). It passes through a panel, bracket or bulkhead and is locked in place, so a brake pipe can pass cleanly from one side to the other – common on classic cars, kit cars, race and rally builds. Supplied by EMS Spares, Leicester.
Specification
| Ends | 2 x 3/8″ x 24 UNF male |
|---|---|
| Pipe size | 3/16″ (4.75mm) – use with female unions (EMS-A1A) |
| Type | Bulkhead union, with brass half nut |
| Hex / spanner size | N/A |
| Overall length | N/A |
| Material / finish | Solid brass, natural finish – rust resistant |
| Weight | 27.5g approx (union), 4.5g (half nut) |
| Interchange reference | HU107* |
| EMS part number | EMS-A107 |
* 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: inline brake pipe connectors explained
What does an inline connector do?
An inline connector (joiner) joins two lengths of brake pipe in a straight line – for repairs where only part of a pipe is corroded, or to extend a pipe. Each end takes a flared pipe with the matching union.
Female-female or male-male?
- Female-female joiner (EMS-A20): both ends are threaded holes – each pipe end needs a male union (EMS-A1).
- Male-male connector (EMS-A23): both ends are male threads – each pipe end needs a female union (EMS-A1A).
- Bulkhead union (EMS-A107): a male-male connector that passes through a panel or bracket and is locked with a half nut.
Identify your thread
| 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.
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.
Note: a correctly made flared joint is a permanent repair. Never use compression fittings on brake pipes.
Pack sizes
1, 3 or 5 bulkhead unions, each with a brass half nut.
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
Is the nut included? Yes – one 3/8″ UNF brass half nut with each union.
What hole size do I need? Drill the panel just over 3/8″ (about 10mm) so the thread passes through, then lock with the half nut.
Need help? Message us with your vehicle.
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