Author: Haroon Khalil

The angle section may be of equal or unequal legs (Fig. 24.1(a)) and available in different sizes. Angle sections are used in steel roof trusses, steel columns, beams and as stiffeners in girders.

Flats are plates with longer length with shorter width. The width varies from 18 to 500 mm and thickness from 3 to 80 mm. Flats are comparatively costlier and used in grill works and railings.

Rolled plates with thickness of 5–28 mm and with a maximum area of 30 m2 are available. Thin plates with 5 mm thickness are called sheets. These are used in flanges of beams and columns and as column bases.

Bars are of round or square cross-sections. Square sections of size 5–32 mm are commonly used. Round bars of diameter 6–32 mm are available. Both are available in lengths of 10–12 mm. Square bars are used for railings and of grill work and round bars are used in reinforced concrete and brick works.

In order to use in construction works, steel should be available in certain forms which are known as steel sections in commercial forms or market forms. Some of the common sections or forms are given below.

Steel is used in large extent in different forms in buildings. The materials generally used for structural purposes are cast iron, wrought iron and steel. As cast iron can withstand only compression, it is used limitedly. Wrought iron could resist tensile stresses. But mild steel can withstand both. Hence, it has replaced cast iron and…