NPT vs BSP: Are They Interchangeable?
No. NPT and BSP threads are not interchangeable and must not be mixed on the same connection. NPT uses a 60-degree thread angle, while BSP uses a 55-degree angle. Their thread forms and pitches also differ across many sizes.
Although the fittings may appear similar, they will not mate correctly or form a reliable pressure seal. For BSP connections, browse our stainless steel fittings range. NPT-to-BSP adaptors are also available in 316 stainless steel when connecting components with different thread standards.
316 Stainless Steel NPT Fittings
Our range covers the most common screwed connection types for industrial and process piping:
- Plugs
- Nipples
- Hose tails
- Sockets
- Elbows
- Adaptors, including NPT-to-BSP options
For hygienic applications requiring a quick-release sanitary connection, see our tri-clamp range.
Source NPT Fittings from Inox Fittings Australia
Need help choosing the correct size, thread standard or end connection? Contact Inox Fittings Australia to discuss your requirements or request a quote.
FAQs
What does NPT stand for?
NPT stands for National Pipe Taper, the American standard for tapered pipe threads governed by ANSI/ASME B1.20.1.
Are NPT and BSP threads interchangeable?
No. They use different thread angles, thread forms and, across many sizes, different thread pitches. Use a purpose-made NPT-to-BSP adaptor when connecting the two standards.
How do I measure an NPT thread?
Measure the outside diameter of the male thread with a calliper and compare it against the size chart above. Because NPT sizes are nominal, the measured outside diameter will be larger than the stated NPT size.
Do NPT threads need thread tape or sealant?
Yes. PTFE tape or a suitable thread sealant should be applied to ensure a leak-free joint. Apply tape in the direction of the thread to prevent it from unravelling during assembly.
