Brass Hose Barb to BSP Thread Connector – 1/4” 3/8” 1/2” Male Female Reducer

Description

Brass Hose Barb to BSP Thread Connector – 1/4” to 1/2” Male/Female Reducer

A precision-machined brass fitting that transitions between a barbed hose tail (for flexible hose) and a BSP threaded port (for rigid pipe or equipment). The barbed tail grips the inner bore of flexible hose; the BSP thread connects to valves, pumps, compressors, and manifolds. Available in male BSP (external thread) and female BSP (internal thread) configurations, and in reducing variants that connect two different hose or pipe sizes in a single fitting.

Key Specifications

Material: Free-machining brass (CuZn39Pb3)
Thread Standard: BSP (BSPP — parallel thread, ISO 228-1)
BSP Sizes: 1/4”, 3/8”, 1/2” (male or female, select above)
Hose Barb ID: Matches nominal hose inner diameter (e.g., 1/4” barb for 6mm ID hose)
Working Pressure: Up to 150 PSI (10 bar) for water/air; lower for fuel applications
Temperature Range: -20°C to +120°C
Media: Air, water, fuel, light oil (verify chemical compatibility for aggressive fluids)

Hose Barb Sizing — ID vs OD Explained

Hose barb fittings are sized by the inner diameter (ID) of the hose they accept, not the outer diameter. This is a common source of ordering errors:

A 1/4” (6mm) barb fits hose with 6mm inner bore — the hose OD will be larger depending on wall thickness
A 3/8” (10mm) barb fits hose with 10mm inner bore
A 1/2” (12mm) barb fits hose with 12mm inner bore

Always measure the hose inner bore, not the outer diameter, when selecting a barb fitting.

What Questions Does This Product Answer?

"Do I need PTFE tape on a BSP hose barb fitting?" — BSPP (parallel) threads do not self-seal. Use a bonded seal washer (dowty washer) on the male thread shoulder, or apply PTFE tape as a temporary measure. For permanent installations, use anaerobic thread sealant (e.g., Loctite 577).
"What hose clamp should I use with a brass barb fitting?" — Use a worm-drive (Jubilee) clamp or ear clamp positioned 5–10mm from the end of the barb. For high-pressure applications, use two clamps per barb. Avoid over-tightening on brass barbs — the soft brass can deform.
"Can I use brass fittings with fuel?" — Yes for petrol (gasoline), diesel, and light oils. Not suitable for ethanol concentrations above E20 or aggressive solvents. For E85 or methanol fuel systems, use stainless steel or PTFE-lined fittings.
"What is the difference between a reducing barb and a straight barb?" — A straight barb has the same hose ID on both ends. A reducing barb has different IDs on each end, allowing connection between two different hose sizes in a single fitting.

Typical Applications

Automotive: Coolant hose connections, fuel line adapters, vacuum line fittings, intercooler hose connections
Air compressors: Flexible hose to compressor outlet, regulator inlet connections
Irrigation: Garden hose to threaded valve connections, drip system adapters
Marine: Bilge pump hose connections, raw water intake fittings, fuel tank vent adapters
Industrial: Coolant system hose connections, lubrication line adapters, hydraulic return line fittings

Installation Notes

Push hose fully onto the barb until the hose end contacts the fitting shoulder — partial insertion causes leaks and hose blowoff under pressure
For fuel and high-pressure applications, use a proper hose clamp rated for the application pressure
Apply thread sealant to the BSP thread before assembly; do not rely on thread interference alone for BSPP parallel threads
Inspect brass fittings for dezincification (pitting, white powder deposits) in high-chloride water systems; replace if dezincification is evident