Durable; tough; resilient.
Inflexible or without exception.
Made of cast iron.
A hard and brittle, but strong, alloy of iron, carbon, and silicon, formed by casting in a mould.
Characterised by force or vigour; full of energy; lively, vigorous.
Possessing or pertaining to energy.
Any material utilized for its release of energy, either as an explosive, propellant, or for pyrotechnic effects.