My grandfather worked at an ironworks when he was young.
There are several small ironworks in this town.
鉄工所 usually means a smaller ironworking or metalworking shop, whereas 製鉄所 is a large-scale industrial plant that smelts iron ore into steel.
Standard modern kanji spelling.
Outdated kanji form using 鐵 (old form of 鉄).
Compound of 鉄 (iron) + 工 (work, craft) + 所 (place).