I have a new product project that needs a 1/4-20 threaded stud x 2" long,
attached to a 3/16" thick steel strip. I could just use a bolt but the bolt
head would get in the way. A carriage bolt would work but would involve
punching a square hole in the 3/16" strip. Is there a off-shelf fastener
that I could stake in the strip? I've seen such but what do you call them
and are they standard off-shelf part? Would it be cheaper to bite the
bullet and punch the square hole? (I hate square punches and dies!)

It'll be a cool product and I'll explain all once I get legal status on it.
And, I have a new computer controlled wire wheel machine that is almost
done, it just needs programming and fixturing. WAY COOL! 1k units a day
(on paper) with almost no operator training. We're already starting to make
parts for three more. I could buy such machines from Germany at $180k
each.