pipes
Stuff about pipes (different sizes, couplings, how to solder them, etc.)
thread
conisch: BSPT = iso 7 = https://www.engineeringtoolbox.com/iso-threads-d_752.html = British Standard Tapered Pipe NPT
recht: BSP metrisch
file:///home/user/Downloads/ip_duursma_poster_uitwendig_schroefdraad_meten.pdf
https://www.acess.nl/dbdocs/file_4.pdf schroefdraad herkennen
https://vanderworp.org/nl/werktuigbouw-schroefdraad/
Threads for gasses: https://www.jewagas.com/nl/blog/aansluitingen-voor-technische-en-industri%C3%ABle-gassen-een-overzicht
inch D buiten D binnen 1/16 7,723 6,561 1/8 9,728 8,565 1/4 13,157 11,445 3/8 16,662 14,95 1/2 20,955 18,633 5/8 22,911 20,589 3/4 26,441 24,12 1 33,249 30,292