# How to determine the weight of mild steel bar in MKS system

In this civil engineering article, you will learn how the formula W = D^{2}/ 52.9 x L is derived for Mild Round Steel Bar weight calculation.

Assume the length of the bar as 20 feet and diameter of the bar as #4 i.e. 4/8 inches.

We know, 1 inch = 8 sooters

and 1 soter = 1/8 inch

The weight of the mild steel bar will be calculated as follow :-

W = D^{2} / 52.9 x L

Here, W denotes weight of mild steel bar in Kg, D denotes diameter or numbers of bar and L denotes length of the bar.

After putting all the values, we get the following result :-

W = 42/52.9 x 20 = 6.04 Kg

Now, Weight = volume x unit weight

or, W = X-sectional area x length x 222.32

For mild steel, unit weight is taken as 7850 kg/m^{3} or 222.32 kg/ft3

As steel bar is circular in section, W = pD^{2}/4 x L x 222.32

To divide the unit weight of feet to sooter, divide it with 96 i.e. W = pD^{2}/4 x 962 x L x 222.32

(1 feet = 96 sooter or 12 inch = 96 sooters)

W = 698.438 D^{2} x L / 36864

W = 0.01894634332 D^{2} x L

In friction form, it can be written as follow :-

W = 1/ 52.9, since 1/52.9 = 0.018946

or, 1 D^{2}/52.9 x L

or, D^{2}/52.9 x L

To learn the process in detail, go through the following video tutorial.

Video Source: SL Khan