Air Filter Nut Thread

[111Robin]

What's the thread form on the carb studs for the wing nut ?. 5/16 UNC ?.

[bwaminispeed]

Pretty much all threads on SU stuff is BA, BSF, or, BSW I think, whether that carried over to the intake elbows, I don't know, but, would expect them to be BSW something or other........

[iain1967s]

The diameter and pitch is 1/4”-20

Don’t know if it’s 55° BSW or 60° UNC, but I would assume BSW.

Both are close enough to be effectively interchangeable.

Here’s a 1/4-20 bolt going through a 1/4 UNC die and into the air filter nut...

[111Robin]

Thank you