AN , as in AN fittings refers to army/navy, a standard that was established
for them
in the military industry spec. there are varoius thread sizes ,
ase,uss,acme,npt & more! if you are using one of these thread types, a normal
tap or die
will do,except on precision threads, to check the threads for fit, there are
go/no go thread guages to check the threads produced for proper sizing and so
on. for most things, a standard tap or die will do as long as the fit is fairly
good my 2 pennys worth
steve jones n212kr
