Introduction

Steel structures are built up with hot — rolled steel sections

• Hot — rolled steel sections are made up of structural steel
• IS 800-2007: code of practice for use of structural steel in general building construction.

Types of structural steel:

• IS 226 (Standard Quality)
• IS 2062 (Fusion welding Quality)
• IS 961 (High tensile steel)
• IS 1977 (Ordinary Quality)
• IS 8500(Medium & high strength qualities)

IS 226(Standard Quality):

• Most commonly used steel for general construction purposes of buildings, bridges, industrial structures, transmission line towers etc.
•  Riveting, bolting can be done for all thickness but welding is permitted for thickness ≤ 20mm only
• Carbon content: 0.23 to 0.25%, Elongation: 23%
• Designated as : Fe 410 — S

IS 2062: (Fusion welding type):

• Steel commonly used for general construction purpose, particularly suitable for structure subjected to dynamic loads and impact such as bridge decking, girders and crane girders.
•  Designated as Fe 410 WA, Fe 410 WB, Fe 410 WC.
• Suitable for welding in all thickness.
•  Carbon content (max) 0.20 — 0.25%, elongation: 23%

IS 961 (High tensile steel):

• Greater strength and atmospheric corrosion resistance
• Fe 570 — HT: For structure with fabrication by methods other than fusion Welding.
• Fe 540 — W — HT: For structures where fusion welding is involved.
• Carbon content  ≈ 0.27 % for Fe 570 - HT, Elongation = 20%

Physical properties of  structural Steel

Various types of rolled structural steel section

• Rolled steel I-sections (beam section)
• Rolled steel channel sections
•  Rolled steel Tee sections
• Rolled steel angle sections
• Rolled steel bars
• Rolled steel tubular sections
• Rolled steel flats
• Rolled steel plates
• Rolled steel sheets etc

 I—sections:

• Indian standard junior beam (ISJB)
• Indian standard light beam (ISLB)
• Indian standard medium weight beam (ISMB)
• Indian standard wide flange beam (ISWB)
• Indian standard heavy beam (ISHB)
• Indian column section (SC)
• An I — section is designated by its depth and weight

Eg: An ISLB 500 at 735.75 N/m means, An I—section is 500 mm deep and self weight is 735.8 N per meter length.

 Channel Sections:

• Indian standard junior channel (ISJC)
• Indian standard light channel (ISLC)
• Indian standard medium weight channel with sloping flange (MC)
• Indian standard medium weight channel with parallel flange (MCP) 
• Indian standard gate channel (ISGC)
• Designated by its depth and weight

Eg: ISLC 350 at 380.63 N/m

T—Sections:

• Indian standard rolled normal T — section (ISNT)
• Indian standard rolled deep legged T — (ISDT)
• Indian standard rolled slit light weight T —bars (ISLT)
• Indian standard rolled silt medium weight T — bars (ISMT)
• Indian standard rolled silt T — bars from H — section (ISHT)
• Designation: ISNT 125 at 274 N/m

Angle sections:

• Indian standard equal angles, Indian standard unequal angles and Indian standard bulb angles.
• Designated by abbreviation ISA along with lengths of both legs and thickness.

Eg: ISA 75 x 75 X 6 mm