### How To Calculate Weight Of Mild Steel Bar

Mild steel is a plain low carbon steel without any alloying elements. It is very ductile and is used as a structural steel for ordinary applications in civil construction so it’s very important to know how to calculate weight of mild steel bar.
Here we are going to explain how to calculate unit weight of steel:
we know that:
Weight = Volume x Density
Volume we can get from Diameter of steel and height of steel.
So Volume of steel bar = A x H    ,        so here    A = area of steel        H = Height or length of steel one meter
Here we have to Find out Unit weight of steel for 1 meter steel
Dia of steel = D = 8 mm       ,      Length of Steel = 1 meter
Find volume of Steel bar
Volume of bar = 3.14 x (0.008)2 / 4  x 1
Volume of bar = 0.00005024 m3
We know that density = 7850 kg/m3
So Weight of 1 meter steel
Weight of steel = Volume of Steel x Density of steel
Weight = 0.00005024 x 7850 = 0.395 kg
Given formula can be used to find out the unit weight of steel :
Unite of Steel = D2/162
Let’s Check    we will use the 8mm dia of steel you can use the different diameter of steel but in mm.
D2/162 = (8)2/162 = 0.395 kg        (This is the weight of 1 meter steel )
For 6 mm steel the weight is 0.222 kg/m
For 8 mm steel the weight is 0.395 kg/m
For 10 mm steel the weight is 0.616 kg/m
For 12 mm steel the weight is 0.888 kg/m
For 16 mm steel the weight is 1.578 kg/m
For 20 mm steel the weight is 2.466 kg/m
For 25 mm steel the weight is 3.853 kg/m
For 32 mm steel the weight is 6.313 kg/m
For 40 mm steel the weight is 9.865 kg/m
The above Unite Weight Of Steel we can Find out with  D2/162 formula
PROOF OF D2/162
Unit weight of steel (for 1 meter length) = D2/162 = (8)2/162 = 0.395 kg
Both the values are same, which means the formula is right.
For different lengths, weight of steel = d2/162 x length
Here we are going to explain how it has been arrived D2/162 (Note: D unit is in MM)
Density of Steel (in Kgs/Cu.m) = Weight of Steel (in Kgs)/Volume of Steel (in Cu.m)
So,
Weight of Bar (in Kgs) = Volume of Steel Bar (in Cu.m) X Density of Steel Bar (in Kgs/Cu.m)
Data:
Volume of Steel Bar (Cu.m) = Area of Steel Bar (sq.mtr) X Length of Steel Bar (mtr)
Since We are trying to calculate the unit weight of Steel Bar, the length of Steel Bar in the calculation would be 1 mtr or 1000 mm.
Area of Steel Bar = (3.14 X D^2)/4
Density of Steel Bar = 7850 Kgs/Cu.m = 7850/(1000X1000X1000) Cubic mm
So considering these data in the Weight formula we get
Unit Weight of Steel Bar (in Kgs) = (3.14 X D^2)/4 X 1000 X 7850 / (1000 X 1000 X 1000)
= D^2 X (0.006162)
To simplify, we can reciprocate the decimal figure here i.e., (1/0.006162) and get a figure of 162.28
Unit weight of Steel Bar (in Kgs) = (D^2)/162.28 ~ (D^2)/162
Where D is the Diameter of the Steel Bar in mm.