Some BSP and GAS threads are the same 14 TPI.......
Seeing where you live there must be lots of that stuff still around.......
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Some people called pipe threads Gas but officially there is no such thing. Town gas plumbing in Oz always used BSP threads. Pre WWII a lot of USA tap and die makers called BSP tools Whitworth and one occasionally still encounters old US made pipe threading tools marked "W". This is because at that time this was the only Whitworth form thread used in the USA.
You have in common use in Australia BSPT, BSPP, NPS, NPT, NPT Dryseal, and a few other variants of NP. Metric Conduit threads are often encountered. Easy to recognise as they are all 1.5mm pitch.
BSPT & BSPP are accepted as an ISO system and called ISO R and ISO G.
unofficially i have a full set markde GAS
https://www.aulro.com/afvb/images/im...010/01/808.jpg
LAL brand and very old, probably pre WWII. Lanham, Archer, and Lane.I don't think they still exist.
The British Standard was BS Pipe, and the term gas was never used in a standard.
I can't read the size on that tap but 14tpi makes it either 1/2", 5/8", 3/4", or 7/8". 5/8" and 7/8" are BSPP only, not BSPT.