noun
steel frame; steel beam; steel girder
Refers to steel structural members used in building construction, such as beams, columns, and girders. Often used in compounds like 鉄骨造 (steel-frame construction).
このビルは鉄骨でできている。
This building is made of a steel frame.
鉄骨の組み立てが始まった。
The assembly of the steel frame has begun.
鉄筋 refers to steel reinforcing bars used inside concrete, while 鉄骨 refers to larger structural steel members like beams and columns.
Compound of 鉄 (iron/steel) and 骨 (bone/frame), literally 'steel bones'. The term reflects the skeletal role of steel in modern construction.