The Internal Structure or the "skeleton" of the BattleMech of which all other 'Mech equipment is attached. The "skeleton" is made up of several dozen "bones." Each Bone is a honeycombed, foamed-aluminum core wrapped with stressed silicon-carbide monofilament and protected by a rigid, titanium-steel shell. Each of these artificial bones has attachment points for myomer "muscles" and servos that drive the BattleMech. The skeletal construction helps make BattleMechs less vulnerable and easier to repair than vehicles supported by stressed-skin shells.
The basic skeleton of a 'Mech.
Endo Steel was specially designed for use in 'Mech skeletons. Constructed by Zero-G manufacturing techniques that uniformly mix high-density steel with lower-density titanium and aluminum, the resulting metal is twice as strong per unit per unit of weight as standard skeleton material but considerably bulkier.