Fuel/Tanks Series A Tank Holding Bolts

[Joe]

Hi,
does someone have infomation about correct bolts (4) to hold a Series A tank to the frame ?
Diameter should be 3/8", but what threat?
Sorry, can`t feel it as threats messed with mix of wrong bolts (BSF3/8- 20G and UNF 3/8 - 24G).
Cheers Joe

 

[Marvel]

Cycle thread so 26tpi

 

[Joe]

Thanks Marvel,
so was my assumption - thanks for clarification.
So will try to cure starting with smaller diameter.