Assuming no counterbore and space is not a problem, how do you
choose between hex head and hex socket head ?

I've noticed that hex head screws are commonly available up to
property class 8.8 while hex socket head screws go up to 12.9.
Why is that ?

--
André Majorel http://www.teaser.fr/~amajorel/
"The object of this year's expedition is to see if we can find
trace of last year's expedition."