BSP Female Threaded Pipe Reducer Coupling — Stainless Steel A2, 1/2" to 4"

Measure the outer diameter of your existing pipe threads and match it to the BSP nominal size. As a reference, a 1" BSP pipe has an outer thread diameter of approximately 33.25mm (≈1-5/16"). If you are reducing from one pipe size to another, select the variant that lists both sizes — for example, "1" to 1.5" female" means a 1" BSP inlet and a 1.5" BSP outlet. When in doubt, contact us to confirm before ordering.

A2 stainless steel (304 grade) generally offers a tensile strength of around 500–700 MPa, making it suitable for typical residential and light commercial plumbing, water supply, and low-pressure gas lines. For high-pressure industrial applications, verify the working pressure rating against your system specifications before installation.

Yes. A2 stainless steel is corrosion-resistant and performs well in outdoor, humid, and wet environments. It is generally suitable for freshwater plumbing, irrigation systems, and exposed pipe runs. For marine or highly chlorinated environments, A4 (316) stainless steel is typically recommended for longer service life.

Yes. These couplings use BSP (British Standard Pipe) female threads, which are compatible with BSPP (parallel) threaded pipes and fittings. BSP threads are widely used in plumbing systems across the UK, Europe, Australia, and Asia. They are not directly compatible with NPT (National Pipe Taper) threads used in North American systems — an adapter is required if connecting to NPT-threaded components.

For a leak-free connection, applying PTFE thread tape or a suitable pipe thread sealant compound is generally recommended, especially on parallel (BSPP) threads. This is standard practice for most threaded pipe fittings regardless of material, and helps compensate for minor surface variations in the thread engagement.

A standard coupling connects two pipes of the same diameter. A reducer coupling (also called a reducing coupling or pipe reducer) connects two pipes of different diameters, allowing you to transition from a larger pipe to a smaller one — or vice versa — within the same run. Select the variant that matches your inlet and outlet pipe sizes. Variants listed with a single size (e.g., "2" female") are straight couplings; variants with two sizes (e.g., "2" to 3" female") are reducers.

These fittings are typically used in residential and commercial plumbing, water supply lines, irrigation systems, compressed air lines, and low-pressure gas distribution. They are also commonly used in industrial fluid handling where BSP-threaded connections are standard. Always verify the pressure and temperature ratings are appropriate for your specific application.