鉄

1. Origins, structure, and basic meaning

• Structure: 鉄(てつ) denotes the metal iron and is also used when discussing it as a nutrient.
• Basic usage: It states that a large amount of iron was used in the bridge's framework.
  • この橋の骨組みには大量の鉄が使われている。

2. Common pitfalls and similar expressions

• Material and nutrient
  • 鉄の橋 refers to the material of a structure. 鉄を含む食品 refers to the nutrient in food; 鉄分(てつぶん) is also used in this context.