What is a square steel pipe?
- Share
- Issue Time
- Jul 20,2023

Square pipe, as the name implies, is a square tube type, a hollow square cross-section light thin-walled steel pipe, also known as steel cold-bent profile. It is a square cross-section steel made of Q235 hot-rolled or cold-rolled strip or coil as the base material, formed by cold bending and then welded by high-frequency welding.
A square steel pipe is a type of hollow structural section that is made from steel. It has a square-shaped cross-section and is commonly used in various applications, including construction, automotive, and manufacturing industries.


Square steel pipe material: There are two types of ordinary carbon steel and alloy steel, so there are two types of ordinary carbon steel square pipe and low alloy square pipe. Ordinary carbon steel includes Q195, Q215, Q235SS400, 20# steel, 4, 45# steel, etc.; low alloy steel includes Q345, 16Mn, Q390, ST52-3, etc.
Identification of square steel pipe: We can judge by observing the surface smoothness and flatness of the square pipe. If the surface of the square pipe is relatively flat, it can reflect that the square pipe is good. On the contrary, if the surface is not so flat, and the size and thickness are not standardized, it can reflect that the square pipe is a poor quality product.
Square tube specifications
The specification marking method of square tube is mainly expressed by side width*side width*tube wall thickness. For example, 16x16x0.4~1.5 indicates that the side width is 16mm and the tube wall thickness is 0.4-1.5mm.
Welded pipe series:
15*15,20*20,25*25,30*30,35*35,40*40,45*45,50*50,55*55(0.5-6),60*60,65*65,70*70,75*75,80*80,85*85,90*90,95*95,100*100,105*105,110*110,115*115,120*120,125*125,130*130(1.5-10),140*140,150*150,160*160,170*170,180*180,190*190,200*200,210*210,220*220,230*230,240*240,250*250,260*260,270*270,280*280,290*290,300*300-500*500(3-4)