Square pipe is a rolled steel product, which has a specific section shape (most often square, rectangular, flat-oval).
There are welded and seamless pipes. The latter have shown themselves to be more durable, so it is better to use them in structures where pipes will withstand significant loads.
Advantages of square pipes:
The metal center "Ikar" offers certified square pipes, popular in construction ans different types of industry, that comply with GOST 13663-86, GOST 8639-82, GOST 8645-68, GOST 30245-94.