noun
iron industry; steel industry
Refers to the industrial sector involved in iron and steel production, including smelting and manufacturing.
製鉄業は日本の重要な基幹産業の一つです。
The iron and steel industry is one of Japan's key basic industries.
鉄鋼業 is a broader term for the steel industry, while 製鉄業 specifically emphasizes the manufacturing process of iron and steel.
Compound of 製鉄 (seitetsu, 'iron manufacturing') + 業 (gyō, 'industry').