方管以钢管为多数，经过拆包，平整，卷曲，焊接形成圆管，再由圆管轧制成方形管然后剪切成需要长度。一般是50根每包神傲方管在现货方面以大规格居多在10*10*0.8-1.5~~500*500*10-25，方管用途为结构方管，装饰方管，建筑方管，机械方管等。

Square pipes are mostly steel pipes. After unpacking, flattening, crimping and welding, they form round pipes. Then they are rolled into square pipes and cut into required lengths. Generally, 50 square tubes per package are in large specifications at most 10*10*0.8-1.5-500*500*10-25. The square tubes are used as structural square tubes, decorative square tubes, building square tubes, mechanical square tubes and so on. 方管的重量计算公式 ：(边宽a+边宽b-2.8584×壁厚)×壁厚×0.0157×长度, 注意计算单位(边宽与壁厚单位是毫米,长度是米).。 这种方法还适应KQJ、KQF空心钢计算.这种方法比较简单,也容易记,在工矿企业常用.

The formulas for calculating the weight of square pipes are as follows: (side width a + side width b-2.8584 * wall thickness) * wall thickness * 0.0157 * length, pay attention to the unit of calculation (side width and wall thickness are millimeters, length is meters). This method is also suitable for calculation of KQJ and KQF hollow steel. This method is simple and easy to remember. It is commonly used in industrial and mining enterprises.

方管截面的长为a，宽为b，壁后为c，方管长度为l，方管密度为p，则

If the cross-section length of square tube is a, the width is b, the back of the wall is c, the length of square tube is l, and the density of square tube is p, then

重量=(ab-(a-2c)(b-2c))×l×p

Weight=(a b-(a-2c)(b-2c)*l*p

=2c（a+b-2c)×l×p

= 2c(a+b-2c)*l*p

=2clp(a+b-2c)

= 2clp(a+b-2c)

将上面的数字代入上式就可求出方管的重量了。但要注意各值的单位

The weight of the square tube can be calculated by substituting the above figures into the formula. But we should pay attention to the units of each value.

交货重量的计算公式及允许偏差

Calculating Formula and Permissible Deviation of Delivery Weight

（1）边长*4*壁厚*7.85*长度

(1) Edge length * 4 * Wall thickness * 7.85 * Length

（2）4*壁厚*（边长-壁厚）*7.85*长度

(2) 4 * wall thickness * (side length - wall thickness) * 7.85 * length

一般（1)常用。如40MM*20MM*1.5MM 方管长度是850MM，就是：

Generally (1) commonly used. If the length of 40MM*20MM*1.5MM square tube is 850MM, that is:

（20+40）*2*1.5*7.85*850=0.012吨

(20+40)*2*1.5*7.85*850=0.012 tons