'steel-composed' originates from Modern English, specifically the words 'steel' and 'composed', where 'steel' ultimately comes from Old English 'stēel' meaning 'hard metal' and 'composed' comes via Middle English from Latin 'componere' where 'com-' meant 'together' and 'ponere' meant 'to place'.

'steel' changed from Old English 'stēel' and eventually became the modern English word 'steel'. 'compose' changed from Latin 'componere' to Old French 'composer', then to Middle English 'compose' and eventually the past participle 'composed', which combined with 'steel' to form the compound 'steel-composed'.

Initially, the parts meant 'hard metal' and 'to put together (place together)', but over time the compound came to mean 'made of, or consisting of, steel'.