方管，是方形管材的一種稱呼，也就是邊長相等的的鋼管。在抗彎、抗扭強度相同時，重量較輕，所以廣泛用于制造機械零件和工程結(jié)構(gòu)。

Square pipe is a form of address for square pipe, that is, steel pipe with equal side length. When the bending and torsional strength are the same, the weight is lighter, so it is widely used in manufacturing mechanical parts and engineering structures.