Lexan is actually stronger that steel for it's weight, which is one of the reasons that many inner city schools now use them as windows. You can hit them with a concrete block and they will not crack or break. Most of the space-age plastics are much stronger than steel as well. Combinations of boron, graphite and fiberglass are now used in aircraft manufacturing because it's lighter and stronger than traditional aluminum. I think the only reason some keyboard manufacturers still use steel for their housings is because steel is a hell of a lot cheaper and can be stretch formed--not for strength.
------------------ Travlin' Easy
PSR-S950, TC Helicon Harmony-M, Digitech VR, Samson Q7, Sennheiser E855, Custom Console, and lots of other silly stuff!
K+E=W (Knowledge Plus Experience = Wisdom.)