Sockets for Square head bolts
Verify square socket head size here:
Easily drive your square head bolts
These square head sockets are designed specifically to work with impact tools, featuring increased strength and torque, easier access to tight areas and reduced wear. Just remember that if you drive a screw or bolt in to far there is no solution other than filling the hole.
Maybe 3/8" or 1/2" drive depending on availability
Over tightening can cause bolt heads to snap off. Final tightening should be done by hand