方管的三種理論重量算法：關于方管的重量的計算方法，總共有三種方式。第一種，就是用鋼板算法，也就是，將一個正跟的方管展開，然后形成一個四片扁鋼，然后在對扁鋼進行計算。這種計算方法計算出來的重量，會與實際的方管的重量有比較大的差異，比實際的重量重。因為，這種方法會把中間重疊的部分的重量計算在倆面。不過，很多客戶還是比較接受這種重量計算方式的。

There are three theoretical weight algorithms for square pipes: the calculation method of square pipes'weight, there are three ways altogether. The first one is to use the steel plate algorithm, that is, to expand a square pipe with a straight heel, then form a four-piece flat steel, and then calculate the flat steel. The weight calculated by this method will be quite different from the actual pipe weight, which is heavier than the actual weight. Because this method calculates the weight of the overlapping parts on both sides. However, many customers are more accepting of this method of weight calculation. 

第二種方式是圓管算法，在方矩管生產的時候，大部分都是先制作成圓鋼，然后再進行壓痕，所以，只要將計算重量換算成計算稱圓鋼的重量，知道圓鋼的周長與直徑就可以進行計算。這種算法誤差也比較小。第三種是標準算法，是根據日本的JISG3466標準來進行計算的，這種計算方法，重量上基本吻合，不過知道這種計算方式的人卻相對較少一些。

The second way is the circular pipe algorithm. When the rectangular pipe is produced, most of them are first made into round steel, and then indented. Therefore, as long as the calculated weight is converted into the calculated weight of the round steel, the circumference and diameter of the round steel can be calculated. The error of this algorithm is also relatively small. The third is the standard algorithm, which is calculated according to the JISG3466 standard of Japan. The calculation method is basically the same in weight, but relatively few people know this calculation method.