Could the 4 be the tolerance on the wall thickness of 2"Sorry for the lack of info, it's indeed a 48" diameter steel pile and the confusing measurement is indeed for the wall thickness of that steel pile.
2" wall thickness is common in these size piles, just can't make sense of the " and ' :-).
I think that what looks like a ‘ is actually the 1 of 1/4, so 2 1/4” i.e. 2.25 inches. Makes sense in the context.2" wall thickness is common in these size piles, just can't make sense of the " and '