steel frame; steel beam; steel girder
鉄骨を組む作業が進む。
The work of assembling the steel frame is progressing.
高層ビルは頑丈な鉄骨造りだ。
The high-rise building has a sturdy steel-frame construction.
昔の工場の鉄骨がむき出しになり、構造が見える。
The old factory's steel beams are exposed, revealing its structure.