Construction steel can usually be divided into steel for steel structures and steel for reinforced concrete structures. Steel for steel structures mainly includes ordinary carbon structural steel and low alloy structural steel. The varieties are section steel, steel pipe, and steel bar. There are angle steel, I-beam, and channel steel in section steel.

Steel ingots are hot-rolled and processed into steels with various cross-sections called sections (or profiles). According to the different shapes of the section, the section steel is divided into round steel, square steel, flat steel, hexagonal steel, angle steel, I-beam, channel steel, steel pipe, and steel plate. Section steel is the steel for steel structure, and sections of different sections can be made into various steel components as required.

(1) Angle steel: Angle steel is commonly known as angle iron, which is a long strip of steel with two sides perpendicular to each other and is divided into equilateral angle steel and unequal angle steel. Angle steel is widely used in various building structures and engineering structures, such as beams, bridges, ships, warehouse shelves, etc.

(2) Channel steel: Channel steel is a long strip of steel with a groove-shaped section. Channel steel is mainly used in building structures, vehicle manufacturing, and other industrial structures

(3)  I-beam: I-beam is also a steel beam, which is a long strip of steel with an I-shaped section. I-beam is widely used in various building structures, bridges, vehicles, brackets, machinery, etc.

(4)  H-beam: H-beam is an economical section steel with better section mechanical properties developed from I-beam optimization. It is named after its section is similar to the English letter "H". Its characteristics are as follows: the flange is wide, the lateral rigidity is large, and the bending resistance is strong; the two surfaces of the flange are parallel to each other, which makes the connection, processing, and installation easy.