鉄筋

1. Origins, structure, and basic meaning

• Structure: 鉄筋, read てっきん, combines iron 鉄 with bar-like reinforcement 筋 as a construction-material term.
• Basic usage: It denotes the steel bars or material used to reinforce concrete structures, as in 鉄筋を組む.

2. Common pitfalls and similar expressions

• Scope and context
  • 鉄筋 is the reinforcing material itself, whereas 鉄筋コンクリート is a structure combining rebar and concrete.