Universal wrench design

I don't know Snap-On still advertises this but back in the late 70's they bragged about their "flank drive" which meant that the sockets and wrenches drove by putting force on the "flank" of the nut or bolt head, not on the corners. This tool would ONLY put force on the corners, and only 2 of them at that. Therefore, as others have suggested, it would round off the corners.