Self-regenerating molecular armor is a description of the armor layer of a Cybertronian exoskeleton. Any damage taken by it, up to 105 mm shells in the case of Scorponok, will heal fully if the energy is available. The armor can however be destroyed by high-temperature weapons equal to or greater than "a 6000 degree magnesium burn".
This exostructure/skeleton is generated by the core protoform of a Transformer out of its own ultra-dense liquid metal mass and any nearby matter it can capture. It can be altered in mere moments when a trans-scan of a new alternate form is taken.