BSPP is also known as British Standard Pipe Parallel. This gage checks the internal parallel threads that do not create pressure-tight joints. They utilize GO/NOGO members which allows the user to accurately check the tolerance of the thread profile. The standard of compliance for this gage is ISO 228-1 and ISO 228-2.
ISO 228 ‐ 1 covers pipe threads where pressure‐tight joints are not made on the threads. ISO 228 ‐ 2 covers the limit gages for pipe threads where pressure‐tight joints are not made on the threads. BSPP thread plug gages have a 55 degree thread profile. This specification covers many GO and NOGO gages that are used to verify different elements of the thread. The GO gage insures that the profile of the machined piece does not exceed the maximum of material provided for by the tolerances applied to the dimensions of the profile defined by ISO 228‐1. The NOGO gage for the threads of the pieces fix the minimum material limit on the flanks of the thread. WESTport provides a complete line of BSPP British Standard Pipe Parallel Thread Gages. Free Technical support is available from our core of engineers to assist you with any questions you may have.