UNIT WEIGHT OF STEEL BAR PER METER

Diameter of bar	Weight (kg/m)	Weight (kg/ft)
6 mm	0.22 kg/m	0.068 kg/ft
8 mm	0.395 kg/m	0.12 kg/ft
10 mm	0.616 kg/m	0.19 kg/ft
12 mm	0.88 kg/m	0.27 kg/ft
16 mm	1.578 kg/m	0.48 kg/ft
20 mm	2.466 kg/m	0.75 kg/ft
25 mm	3.853 kg/m	1.172 kg/ft

 By using the formula D²/162 we calculate the unit weight of steel bar per meter

 By using the formula D²/533 we calculate the unit weight of steel bar per meter

Note:

Length of TMT Steel rod will be 12 meter (or) 40 feet.

What Is Unit Weight?

Unit weight of any substance is defined as the ratio of mass or weight per unit volume. It is usually measured in gm/cm, lb/ft,  or, kg/cm or kg/m etc.

The unit weight of materials varies depending on their composition & properties of ingredients. It gives an idea about the weight or lightness of the materials.

What Is Unit Weight of Steel?

The density of steel is around 7850 kg/m³ (or) 7.85 g/cm³ (or) 490 lbs/ft³ (or) 13231 lbs/yd³.

The various steel diameters used in construction are 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, 25 mm, 32 mm and 40 mm.

The Formula Used To Calculate Weight of Steel

The formula used to calculate the unit weight of steel bars is D²/162.                 Where, D = Diameter of steel bars, 162 is a constant value.

Derivation of formula for calculating unit weight of steel

Derivation of Formula for Calculating Unit Weight of Steel

 Derivation of Formula for Calculating Unit Weight of Steel

 As we know the density of steel = 7850 kg/ m³

Weight of steel per metre  = Volume × Density [ Volume = Area × Length ]

= π/4 x d²× 1000 × 7850 kg/m³ (length = 1000 mm)

= 0.785 × d²× 1000 × 7850 kg / (1000 × 1000 × 1000) [ 1 metre = 1000 mm ]

= 785 x d²× 0.00000785

=  d²/1 × 0.00616225 /1

=  d²/1/0.00616225

=  d²/162.27 ≈

= d²/162 kg/m (say)

So the Formula for unit weight of steel in kg/meter is = d²/162

 

Unit Weight of steel bar per feet = d²/(162.27 x 3.28084)    ( 1 metre = 3.28084 feet)

= d²/532.38 ≈

= d²/533 (say)

=d²/533 kg/feet

 

How do you Calculate the Unit Weight of Steel Bars?

With the help of the formula d²/162 (d is the diameter of the steel bar), we can calculate the unit weight of the steel bars, and it will give us weight in kg per meter. And the formula d²/533 will provide us with weight in kg per foot.