It is important to calculate the unit weight of steel bars of different diameters for preparing bar bending schedule.
How To Calculate Weight Of Steel Bars:
After estimating, it is very important to know the unit weight of steel bars because we estimate them as 100 meters 20 mm ø bar, or 100 feet 16mm ø bar, etc (ø is the symbol of diameter). But steel bar suppliers will not understand this notation, and they measure the steel bars in weight.
So we have to order them in kg or quintal or ton. This article will discuss how to calculate the unit weight of steel bars of different diameters by using the steel weight formula.
Here is the steel weight formula W = D²L/162
Where
- W = Weight of steel bars.
- D = Diameter of steel bars in mm.
- L = Length of bars in meter.
Example 1: Calculate the weight of 60 meters long 12 mm ø bar.
Here,
- D = 12 mm.
- L= 60 m.
We know that,
- W = D²L/162
W = 12² x 60/162 = 53 kg
- Weight of 60 m 12mm ø bar is 53 kg.
Let’s look for another example.
Example 2: Calculate the weight of 100 m 16 mm ø bar.
Here,
- D = 16 mm.
- L = 100 m.
W = 16² x 100/162 = 158 kg.
If we put 1 meter length for each diameter of steel bar in the formula then we will get the unit weight.
- 6 mm ø bar = 6² x 1/162 = 0.222 kg/m
- 8 mm ø bar = 8² x 1/162 = 0.395 kg/m
- 10mm ø bar = 10² x 1/162 = 0.617 kg/m
- 12mm ø bar = 12² x 1/162 = 0.888 kg/m
- 16mm ø bar = 16² x 1/162 = 1.580 kg/m
- 20mm ø bar = 20² x 1/162 = 2.469 kg/m
If we multiply the length of bars by this unit weight, we will get the total weight of steel bars. For example, the total weight of 1000 meter long 20mm ø steel bar is,
1000 x 2.469 = 2469 kg.
Using the same method we can calculate the unit weight of different steel bars. Here I have calculated in meter but we can also calculate in feet. To calculate in feet we have to use the following formula:
- W= D²L/533
Where
- D = Diameter of bars in mm.
- L = Length of bars in foot.
Also Read
Types Of Steel Rebars Used In Construction
How To Calculate Steel Quantity For Beam, Column & Slab
How To Calculate Weight Of MS Plates
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how do you obtain the formula?
This is very helpful for those in management position who are oblige to perform quantification in terms of construction schedule planning. I want and kindly request full time subscription in your daily newsletter.
Tnx for information calculate unit of steel bars and I hope u will gave me some information of civil work next tme
Pls keep it up
Thanking you sir
1st example in answer
in L=100m, and
in question L=60m,
some mistake or confusion are there
Thanks for informing about the mistake. We have updated it as well.
Steel Wight farmul
Thank you very much for putting us through.
But we will like the pdf copy.
Thanks for informition
Really thank you dear sir
You said about L-lenth, W-weight and D-Diametre what about 162? why only 162? not other number? Can you explain it?
To know more you can check out this article http://dailycivil.com/formula-d²l162-calculating-weight-steel-bars-fully-derived/
we dont know what is 162 or where this 162 came from? If You know, please explain what is it.
To know more you can check out this article http://dailycivil.com/formula-d²l162-calculating-weight-steel-bars-fully-derived/
If we have a weight of 6mm iron rod is 2.541 kg of length 11.925 mm
Then why weight of 12 mm iron road is 10.6 kg of length 11.925 mm
Increase 4 times then 6 mm?
Good
So informative… Thanks. Nd keep it up
here what is the meaning of 162? please describe