Stainless Steel 304 Weld Nipple Connector — BSP 1/4" to 4" Threaded Pipe Fitting

Match the BSP size to your pipe's nominal bore (DN number). BSP sizing refers to the bore, not the outer diameter. For example, a BSP 1/2" (DN15) fitting typically has an outer thread diameter of around 20.9 mm (≈0.825"). A BSP 1" (DN25) is typically 33.2 mm (≈1.31") OD at the thread. Always measure your existing pipe thread or check your system's nominal pipe size before ordering. When in doubt, order one size and test-fit before committing to a larger quantity.

Stainless steel 304 weld nipples generally handle working pressures up to 150 PSI for standard schedule pipe applications. Actual ratings depend on wall thickness, operating temperature, and the quality of the welded joint. For high-pressure steam, gas, or process lines, consult a licensed engineer and verify against your system's design pressure.

Yes. 304 stainless steel offers good resistance to atmospheric corrosion, moisture, and many mild chemicals, making it suitable for outdoor plumbing, food-grade installations, and light industrial environments. For highly chlorinated water, saltwater, or marine environments, 316 stainless steel is generally recommended due to its higher molybdenum content.

These are BSP (British Standard Pipe) threaded fittings. BSP threads are not directly interchangeable with NPT (National Pipe Taper) threads used in North American plumbing. While some sizes may appear to engage, the thread angle and pitch differ, which can cause leaks or cross-threading. Use a BSP-to-NPT adapter if you need to connect to an NPT system.

TIG (GTAW) welding is generally recommended for stainless steel 304 weld nipples to preserve corrosion resistance and produce clean, strong joints. MIG welding is also used in less critical structural applications. Use a compatible 308L filler rod and back-purge with argon when welding food-grade, sanitary, or pressure-rated lines to prevent oxidation on the inside of the weld.

These weld nipples are typically compatible with Schedule 10 and Schedule 40 stainless steel pipe in the corresponding DN sizes. The plain (weld) end is sized to match the pipe OD for the given nominal bore. Confirm the outer diameter of your pipe matches the fitting bore before welding, as wall thickness varies between schedules.

Stainless steel 304 weld nipples are commonly used in natural gas and compressed gas distribution systems. However, gas line installations must comply with local building codes and regulations. Always have gas line work designed, installed, and inspected by a licensed professional. Contact us to confirm suitability for your specific gas application.

Each variant is listed as 1 piece. For bulk or project quantities, simply adjust the quantity at checkout. If you need a custom quote for large orders (typically 50+ pieces), contact us directly and we'll work out the best pricing for your project.