H-beam is a kind of Economic section steel, which  sectional area distribution is more optimized, the  ratio of  strength to weight is more reasonable, Mechanical properties of section is more better.

Flat steel, refers to the steel which wide 12-300mm, thick 3-60mm,the rectangular section and with slightly blunt edge .

I-beam, also known as steel beam (English name universal Beam), is a long steel with the section of the I-shaped.

Angle steel, commonly known as angle iron, is a carbon structural steel used in construction. It is a long strip of steel with two sides perpendicular to each other. It is a profile steel with simple section . Angle steel is divided into equal Angle steel and unequal Angle steel.