Plumbing hardware designed to secure flange connections for basins with BSP-threaded brass fittings, the Primaflow Flanged Basin Waste Brass Backnut promises a neat, stable finish. Confidence for installers and competent DIYers comes from clear dimensions and a solid brass construction. Will the nominal BSP sizing match your basin thread and avoid installation errors?
⚡ At a Glance
- • Thread Compatibility: Designed for BSP thread systems; includes sizing clarification for accurate matching
- • Best for: Plumbers and DIY installers who need a durable backnut for basin waste assemblies
- • Not ideal for: Applications requiring non-brass finishes or alternative thread standards
Pack of one threaded brass backnut with a 55mm outer diameter and 10mm thickness. A sizing note explains that a 1 1/4 inch BSP thread actually measures 1 1/2 inches in diameter.
Accurate Thread Fit – Thanks to clear BSP sizing note
BSP thread dimensions are nominal and measure larger in actual diameter; the listing states a 1 1/4 inch BSP thread measures 1 1/2 inches in diameter. That guidance helps identify which nominal size is required for a given measured diameter.
Reduces the risk of buying the wrong backnut by clarifying nominal versus actual thread diameters. Saves time and effort by matching the correct threaded fitting first time.
Durable Seal – With threaded brass fittings
Brass threaded fittings resist corrosion in damp bathroom environments and maintain thread integrity under repeated tightening. The material supports reliable engagement between flange and waste threads.
Provides a long-lasting connection that helps prevent leaks and limits the need for frequent replacements. Suitable where moisture resistance matters.
Easy Tightening – Thanks to a 46mm spanner face
A specified 46mm spanner size gives a clear wrenching surface for applying torque safely and evenly. The 55mm outer diameter and 10mm thickness provide stable contact for the spanner.
Allows installers to achieve a secure, consistent seal without damaging the flange. Practical for tradespeople using standard spanners on-site.
✨ The 4 Key Reasons for Primaflow Flanged Basin Waste Brass Backnut
- Solid brass construction – Long-lasting corrosion resistance in moist bathroom conditions over time
- 46mm spanner size – Allows firm tightening using a common 46mm spanner for installers
- 55mm outer diameter – Matches many basin flange profiles for a neat, secure finish
- Clear BSP sizing note – Prevents fitting mistakes by explaining actual thread diameters measurement
📋 Technical Details at a Glance
- Category: Basin waste backnut
- Brand: Primaflow
- Material: Brass
- Thread standard: BSP (British Standard Pipe)
- Nominal thread size: 1 1/4 inches BSP
❓ Frequently Asked Questions
Q: How do I know if this backnut will fit my basin waste?
A: Measure the actual thread diameter; because BSP nominal sizes differ from actual diameters, a 1 1/4 inch BSP nominal thread measures 1 1/2 inches in diameter, so match the measured diameter to the sizing note.
Q: What spanner size is required for tightening?
A: A 46mm spanner is specified for the backnut, providing the correct face for tightening.
Q: Is the backnut made of brass and supplied as a single unit?
A: Yes, the listing describes threaded brass fittings and is supplied as a pack of one.
🏆 Our Verdict
Suitable for plumbers and DIY installers who need a durable, correctly sized backnut for BSP basin wastes. Clear BSP sizing guidance combined with solid brass construction and practical dimensions makes installation straightforward and reduces the risk of rework. Long-term value comes from corrosion-resistant material and accurate fit that limits leaks and maintenance.
