Steel Manufacture
Preferably specified by a planner/engineer, the frame structure is assembled with longitudinal and transverse reinforcing bars (stirrups), usually with steel diameters 6, 8, 10, 12, 16, 20, 25 and 32 which give tensile strength (if necessary, help to compression), thus also contributing to the resistance to flexure efforts. The stirrups confer resistance to torsion and transverse effort.
The torsional resistance is also influenced by the longitudinal reinforcement.