304 Stainless Steel BSP Female End Cap & Hollow Plug Pipe Fittings | 1/8" to 2"

A BSP female end cap threads onto an exposed male BSP pipe end and closes it off — typically used when you have a pipe stub or nipple sticking out that needs to be capped. A BSP hollow plug (hex plug) threads into a female BSP port or fitting to seal it from the inside. Both seal open pipe ends, but they mate with opposite thread types, so selecting the correct one depends on whether your open end is male or female.

BSP nominal sizes refer to the bore (inside diameter) of the pipe, not the actual thread outer diameter. For example, a 1/2" BSP fitting has an actual thread OD of approximately 20.9 mm (≈0.82"). To find your size: measure the OD of the male thread or the ID of the female port, then cross-reference a BSP thread chart. As a general guide:

• 1/8" BSP — thread OD typically ≈9.7 mm (≈3/8")
• 1/4" BSP — thread OD typically ≈13.2 mm (≈1/2")
• 1/2" BSP — thread OD typically ≈20.9 mm (≈13/16")
• 1" BSP — thread OD typically ≈33.2 mm (≈1-5/16")
• 2" BSP — thread OD typically ≈59.6 mm (≈2-11/32")

If you're unsure, contact us with your measurements and we'll help confirm the right size.

Yes, generally. 304 stainless steel offers solid resistance to rust, atmospheric oxidation, and mild corrosive agents — making it suitable for outdoor plumbing, garden irrigation systems, and light industrial environments with moisture or mild chemical exposure. For highly aggressive environments such as direct saltwater immersion or concentrated acid/chloride exposure, 316 stainless steel is typically recommended for better corrosion resistance.

304 stainless steel BSP fittings of this type are generally capable of handling working pressures in the range of 150 PSI to 3,000 PSI, depending on the nominal size and wall thickness — smaller sizes typically support higher pressures. For use in high-pressure hydraulic or pneumatic systems, please contact us with your specific size and application so we can confirm the rated working pressure before you order.

No — BSP and NPT threads are not interchangeable. While some nominal sizes appear similar in diameter, the thread forms differ: BSP uses a 55° Whitworth thread angle, while NPT uses a 60° thread angle. The thread pitches also differ across sizes. Attempting to mate BSP and NPT threads can result in cross-threading, poor sealing, or fitting damage. Always verify the thread standard (BSP vs. NPT) of your existing ports before ordering.

It depends on the BSP thread type in your system:

• BSPT (tapered BSP): PTFE thread seal tape or a thread sealant compound is generally recommended to achieve a leak-free seal, as the taper creates the seal through thread interference.
• BSPP (parallel BSP): A bonded seal washer (dowty washer) or O-ring is typically used to seal the face of the fitting rather than the threads themselves. PTFE tape alone is usually not sufficient for parallel BSP.

Check whether your port uses tapered or parallel BSP threads before installation to choose the correct sealing method.

304 stainless steel is widely used in food processing equipment and potable water infrastructure due to its corrosion resistance and non-reactive surface. However, compliance with specific standards such as NSF/ANSI 61 (for drinking water system components) depends on the full system configuration and local regulatory requirements. We recommend verifying applicable codes with your local authority having jurisdiction (AHJ) before installing in drinking water lines.