9 out of ten times its 5/8 or if its metric its a 14 if that dont work try a 9/16ths
A 35mm wrench....
21mm socket or wrench
18mm
5/8
A 10mm wrench, or if you don't have metric wrenches, a 13/32 wrench.
A 1 1/4" wrench will fit a bolt of the same size .
wrench for lug nuts on f250 is 7/8s of an inch there is a metric wrench that fits but i cant remember what size it is
The one that fits it tightly/
10mm
To determine the size of the rounded Allen wrench needed for the task, measure the diameter of the screw head or the hole it fits into. Match this measurement to the corresponding Allen wrench size.
The one that fits.
7/8