Wrong side of the speed wrench avkid. 99% of all 1/2" bolts measure 3/4" across flats. You can find some 1/2" bolt types especially in the nut for it that has a 7/8" across flats, but it's normally 3/4".
7/8" is the size you sometimes use on a cheeseborough, though it is more common to be 15/16" as the next size up as also used on 5/8" bolts such as for truss.