BSP 4-Way Cross Brass Pipe Fitting | 1/2" & 3/4" | Male & Female Thread Configurations

BSP sizes refer to the nominal bore of the pipe, not the outer diameter of the thread. For 1/2" BSP, the thread outer diameter is typically around 20.9mm (≈0.82"). For 3/4" BSP, it is typically around 26.4mm (≈1.04"). The best approach is to measure the thread OD of your existing fitting with calipers, or check the nominal bore stamped on your pipe or valve. When in doubt, bring an existing fitting to compare before ordering.

Brass BSP fittings generally handle working pressures in the range of 200–600 PSI depending on size, wall thickness, and the specific alloy used. For water supply and compressed air at typical residential or light commercial pressures (generally under 150 PSI), these fittings are typically well within rating. For high-pressure hydraulic or industrial applications, please contact us to confirm the exact pressure rating for your chosen variant.

Brass has naturally good corrosion resistance and is commonly used in outdoor plumbing, garden irrigation, and marine-adjacent applications. In most cases, brass performs well in wet and humid conditions. However, in highly saline environments (e.g., coastal saltwater exposure) or where aggressive chemicals are present, additional protection or a different material may be advisable. Contact us to confirm suitability for your specific environment.

No — BSP and NPT (National Pipe Thread, the US standard) are not directly interchangeable. While 1/2" BSP and 1/2" NPT have a similar thread count (14 TPI vs. 14 TPI), the thread angle and form differ, which means they will not seal reliably when mixed. If you need to connect BSP to NPT, use a dedicated BSP-to-NPT adapter fitting. Always verify the thread standard on your existing pipes and valves before ordering.

Male (M) ports have external threads that screw into a female-threaded socket, valve, or fitting. Female (F) ports have internal threads that accept a male-threaded pipe end or nipple. The execution options describe the thread gender on each of the four ports — for example, "Cross M×M×M×M" means all four ports are male-threaded. Choose the configuration that matches the thread gender on your existing pipe ends to avoid needing additional adapters.

A Union connection allows the fitting to be disconnected and reconnected without rotating the entire pipe assembly. This is useful in systems where you anticipate future maintenance, filter changes, or equipment swaps. If your installation is permanent and access is not a concern, the standard (non-union) option is sufficient. If you need to be able to break the connection easily for servicing, select the Union variant.

It depends on the thread type. For parallel BSP (G-thread) fittings, sealing is achieved at the face using a bonded seal washer or O-ring — PTFE tape on the threads alone is generally not sufficient. For tapered BSP (R-thread) fittings, PTFE tape or a thread sealant compound applied to the male threads is typically recommended for a leak-free joint. Check whether your fitting is parallel or tapered, and apply the appropriate sealing method before installation.