鐵

Phono-semantic compound:

金 (“metal, gold, iron”).

𢧤 (zhí / 질 “large, strong”).

Together: “a type of metal” → iron.

Iron often stands for strength, durability, determination (e.g., 鐵人 “iron man,” 鐵石心腸 “iron-stone heart”).

Historically crucial for tools, weapons, and later for railways and industry, giving rise to phrases like 鐵馬 (iron horse = train).

Korean usage: 철 means iron/steel, also metaphorically “firm, strong.”