(I guess the following is a bit off topic)
If you ever find yourself stuck without the correct wrench, look in your scrap box for an Allen head screw that fits over the hex head. Attach some sort of handle to its threads (methods range from a nice turned handle screwed and locked in place to a wood dowel drilled and epoxied in place) and you have a "custom" hex driver. Note: to access some fastners you may need to turn down the Allen head...
While not as durable as a commercial nut driver it may help you making progress on a late night project ;-)