方管的三种理论重量算法：关于方管的重量的计算方法，总共有三种方式。第一种，就是用钢板算法，也就是，将一个正跟的方管展开，然后形成一个四片扁钢，然后在对扁钢进行计算。这种计算方法计算出来的重量，会与实际的方管的重量有比较大的差异，比实际的重量重。因为，这种方法会把中间重叠的部分的重量计算在俩面。不过，很多客户还是比较接受这种重量计算方式的。

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. 

第二种方式是圆管算法，在方矩管生产的时候，大部分都是先制作成圆钢，然后再进行压痕，所以，只要将计算重量换算成计算称圆钢的重量，知道圆钢的周长与直径就可以进行计算。这种算法误差也比较小。第三种是标准算法，是根据日本的JISG3466标准来进行计算的，这种计算方法，重量上基本吻合，不过知道这种计算方式的人却相对较少一些。

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.