A company that makes steel. Steel is iron with a little carbon added, which makes it far stronger — it is what cars, buildings, ships and bridges are built from, so steelmakers are big, heavy industry, and their names are famous in business news. The word almost always means the company, not a person: 'the world's largest steelmaker' means a firm employing tens of thousands. If you want the person you say a steelworker. This is a newspaper and business word. You will meet it in headlines about prices, factories closing, trade fights between countries. Nobody uses it in conversation — you would not ask a new friend 'is your father a steelmaker?' English does this a lot in business writing: it names a whole company by what it produces. Carmaker, drugmaker, chipmaker, toymaker all work the same way, and once you see the pattern you can read all of them.

鋼鐵公司、鋼鐵廠（企業）。注意這是指公司，不是指工人；台灣新聞講中鋼這類企業時就是這個字。工人要用 steelworker。