How to determine the unit weight of steel bars in kg per meter

In this exclusive construction video tutorial, Mukesh Shah, the renowned engineer shows how to work out the unit weight of steel bars with various diameters. The length of the bar is taken as 1 meter.

Suppose, in a truck there are bars with different diameters like 8 mm, 12 mm, 16 mm, 20 mm etc. and you have to determine the total weight of theses bars in kg, then follow these steps :-

Initially, you have to find out the unit weight of each bar with the following formula :-

d2/162 x length = 62 / 162 x 1 = 0.222 kg/meter (for 6 mm dia bar)

By applying the above formula, determine the unit weights of the other bars as follow :-

6 mm = 0.222 kg/meter
8 mm = 0.395 kg/meter
10 mm = 0.617 kg/meter
12 mm = 0.888 kg/meter
16 mm = 1.578 kg/meter
20 mm = 2.466 kg/meter
25 mm = 3.853 kg/meter
32 mm = 6.313 kg/meter
40 mm = 9.864 kg/meter

Suppose, the calculation is done for 20 dia and 25 dia bars.
Full length is taken as 12 mm for both dia.
Suppose, the quantity of 25 dia bar is 3 and 20 dia bar is 2.
Total length = 12 x 3 = 36 meter for 25 dia bar
Total length = 12 x 2 = 24 meter for 20 dia bar

We know, the unit weight of 25 dia bar is 3.853 kg (for 1 meter).
We know, the unit weight of 20 dia bar is 2.466 kg (for 1 meter).

The total weight of the bars will be calculated as follow :-
Total Length x Unit Weight
For 25 dia bar = 36 x 3.853 = 138.71 kg
For 20 dia bar = 24 x 2.466 = 59.184 kg

Thus, in this way, we can make a rough calculation for determining the weight of steel bars in kg.

To get more clear idea, go through the following video tutorial.

Video Source: L & T - Learning Technology