Brake unions/brake line size

[Staxbro]

Needing to remake some brake lines. Out here in the UK, most stuff is metric and classic British cars seem to use quite random fittings.
From what I can tell, I need 3/16 brake line for my 68 Charger, with 3/8 brake unions/fittings.
Does that sound correct?
Also, how many TPI in the unions? 3/8 20TPI seems quite readily available here in the uk, but was wondering if they aren't 24TPI.

All help and advice gratefully received. Am going to make my own to save on shipping and to reach myself something new!
Cheers,
Nick

[John_Kunkel]

The hard brake lines are 3/16" OD and the threads on the flare nuts (except the MC) are 3/8"-24.

https://www.amazon.com/L-3-3-Inverted-Tube-Fitting-Tubing/dp/B06XY8L1DP

[Staxbro]

Great John- that's just the info I needed.