Steel Adapter, 1/4-18 Male NPT To 1/4-19 Female BSPP (British Parallel) Swivel, Straight

For tying those two thread styles together, it’s a straight steel adapter with 1/4-18 male NPT on one side and 1/4-19 female BSPP swivel on the other, so it’s meant to bridge that exact NPT to BSPP connection.

This adapter is specifically designed to transition between 1/4-18 Male NPT and 1/4-19 Female BSPP threads, making it suitable for connecting components with different threading standards.

NPT threads typically rely on a sealant or tape to achieve a pressure-tight seal because of how the tapered thread form works. The BSPP side of this adapter is a parallel thread, so it seals through a different mechanism, usually a bonded seal or face seal arrangement at the port. For the NPT male end going into a tapered female port, you would still want to use thread sealant or PTFE tape in most installations to get a reliable seal. The adapter itself does not come with any pre-applied sealant.