What's the difference between BPT thread and BSPT thread? BPT is British Pipe Thread, right? Then, what's BSPT? The reason I'm asking is because I got a GReddy sandwich adapter to run my oil pressure gauge to, and I need to know what the thread is on the ports. One is M12, and the other two say "1/8 PT", which I assume means pipe thread, but I'm not sure what thread standard it is. I'm pretty sure it's not 1/8 NPT because I tried screwing in some Autometer 1/8 fittings I had lying around, and they didn't thread in very well, and neither did my 1/8 NPT tap(I just tried to thread it in lightly in order to not mess up the threads). I got my gauge used, and it came with a hose that connects to a 1/8 adapter and then to a coupling that adapts to the sending unit, but the other end seems to be missing a fitting, namely another 1/8 adapter that would screw into the sandwich adapter. If I can get a 1/8 to 1/8 male connector, I could just screw it into the sandwich adapter, and then screw on the coupling that adapts to the sending unit, and not have to deal with the hose. Does anyone know what thread standard GReddy uses for their gauges? Is it BPT or BSPT? Also, any ideas on where I can find a 1/8 male to 1/8 male fitting? Any help is much appreciated.

 

I think it's BSP and BSPT. The "T" is for tapered.
Many adapters here:
http://www.adaptall.com/