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Structural steel and its classification

Short answer

Sections are classifed as hot-rolled (I-beams, channels, angles, tees, flats, tubes), built-up (plate girders, box), cold-formed light gauge (C, Z sections), and by local buckling class (plastic, compact, semi-compact, slender). Grades follow IS 2062 (E250, E350 etc.).

What do you mean by structural steel? Explain classification of structural steel sections.

Structural steel is steel (an alloy of iron with 0.15-0.25% carbon, plus manganese, silicon etc.) that is rolled into standard shapes and used to carry loads in buildings, bridges, towers and trusses. It has high strength, ductility and uniform quality, and is covered by IS 2062.

Classification of structural steel sections

A. Hot-rolled sections (IS 808)

  • I-sections: ISLB (light beam), ISMB (medium beam), ISWB (wide flange beam), ISHB (H-beam, used mainly as columns), ISSC (column section).
  • Channels: ISLC, ISMC (light and medium channels), ISJC (junior).
  • Angles: ISA with equal and unequal legs.
  • Tees: ISNT (rolled) and ISHT, ISLT (cut from I-sections).
  • Flats, plates, bars, tubes: ISF, plates, round and square bars, circular/rectangular/square hollow sections (IS 1161, IS 4923).

B. Built-up sections: plate girders, box sections, compound beams (I with cover plates), laced or battened columns, and lattice girders; used when rolled sections are insufficient.

C. Cold-formed (light gauge) sections: formed from thin sheets (1-6 mm) into C, Z, hat and tubular shapes; used for purlins, sheeting rails and light structures (IS 801).

D. By local-buckling behaviour (IS 800:2007): plastic, compact, semi-compact and slender sections.

E. By grade: E250, E350, E410 etc. as per IS 2062.

✓ Answer checked by Claude Opus 5.5 (high effort)

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