'steel-built' originates from English, specifically a compound of 'steel' and the past-participle form 'built' of the verb 'build'. 'Steel' comes from Old English 'stēle' (from Proto-Germanic *stahlą) meaning 'hard metal', and 'built' is the past participle of 'build' (Old English 'byldan').

'steel' changed from Old English 'stēle' (and related Germanic forms) and entered Middle English as 'steel'; 'build' came from Old English 'byldan' meaning 'to construct', yielding the past participle 'built'. The compound 'steel-built' developed in Modern English as a descriptive adjective combining the material and the past-participle form.

Initially the literal sense meant 'constructed from steel'; over time it has also acquired a figurative sense of 'very strong or resilient' when applied to people or abstract qualities.