"Sheetmetal" includes any kind of metal...aluminum too... :S
Military grade is similar in misconception...6061T is used by the military and can be marketed when used in non-military applications as "military grade" aluminum...pure marketing to those not in the know (not educated on the matter)
As said in the initial days of Fords announcement...aluminum is a GREAT material in the proper application, but...IMHO...not for a pickups bed
Why Ford made (according to this video) made the bed thicker than steel 'sheetmetal'... :R
Tensile strength and hardness/toughness for this application is not up to that task
Anyone have a aluminum shovel used for dirt/gravel/etc...other than one made for snow/horse poop/etc ?
Or a chisel, center punch, hacksaw blade, pocket knife blade, etc ? There is a reason for that...
Carbon fiber is nothing more than fiberglass (think window glass spun into fine fibers), but with a higher tensile strength fiber. The binder resins are better than the stuff in fiberglass, but still a resin Bill thanks for bringing that into this discussion...and wonder if folks believe every word... :B
Ditto any of the other materials that are *WONDERFUL* for another application, but IMHO, not a good idea for a working pickup bed