BSPT otherwise known as British Standard Pipe Taper. This type of gage checks joints that are taper external, taper internal and also parallel internal. The standard for BSPT is ISO 7/2 2000 and EN 10226-3. The gages were changed in ISO 7/2 2000 and is now different than BS-21. The product threads remain the same. WESTport provides a complete line of BSPT British Standard Pipe Taper Thread Gages from 1/16 to 6.0-. Free Technical support is available from our core of engineers to assist you with any questions you may have.