Brass BSP Reducing Hex Bushing Adapter – Male to Female (1/8” to 1” BSP)

A precision-machined brass reducing bushing that converts between two different BSP (British Standard Pipe) thread sizes in a single fitting. The external hex body allows full torque application with a standard open-end or adjustable wrench, ensuring leak-free assembly in fuel, water, gas, and oil systems. Available in all common BSP size combinations from 1/8” through 1”.

Key Specifications

• Thread Standard: BSP (BSPP — parallel thread, ISO 228-1)
• Configuration: Male (outer) to Female (inner) — reducing bushing
• Material: Free-machining brass (CuZn39Pb3 / C36000 equivalent)
• Body Style: Hexagon — wrench-flat on all sides for full torque
• Available Sizes: 1/8”, 1/4”, 3/8”, 1/2”, 3/4”, 1” (male × female combinations)
• Sealing: BSPP parallel thread — requires bonded seal washer or O-ring face seal for pressure applications
• Pressure Rating: Up to 150 PSI (10 bar) for water/oil; consult application requirements for gas
• Temperature Range: -20°C to +120°C

BSP vs NPT — Critical Identification Note

BSP (British Standard Pipe) and NPT (National Pipe Thread) threads appear visually similar but are not interchangeable. Mixing BSP and NPT fittings causes cross-threading, leaks, and potential system failure. Identify your thread standard before ordering:

• BSP (BSPP): 55° thread angle, parallel thread, seals via washer or O-ring. Common in European, Asian, and Australian equipment.
• NPT: 60° thread angle, tapered thread, seals via thread interference + PTFE tape. Common in North American equipment.
• Quick check: Use a thread pitch gauge or compare against a known fitting. 1/4” BSP = 19 TPI; 1/4” NPT = 18 TPI.

Typical Applications

• Automotive: Engine oil galleries, fuel rail adapters, coolant system reducers, power steering line adapters
• Hydraulic systems: Reducing ports on hydraulic manifolds, cylinders, and pumps
• Pneumatic systems: Air compressor outlet reducers, regulator port adapters
• Plumbing: Water supply line reducers, boiler connections, radiator valve adapters
• Industrial: Lubrication systems, coolant circuits, pressure gauge port adapters

Installation Notes

• BSPP parallel threads do not self-seal — always use a bonded seal (dowty washer) or O-ring face seal on the male thread shoulder
• Do not use PTFE tape on BSPP parallel threads — it does not provide reliable sealing and can contaminate hydraulic systems
• Tighten to manufacturer torque spec; over-tightening brass fittings causes thread galling and cracking
• For gas applications, verify pressure rating and use appropriate thread sealant approved for gas service

Package Contents

1 × Brass BSP reducing hex bushing adapter (size as selected above).