While the Internet offers many calculators for figuring out the weight of steel round bars, it is better to know the formula yourself. You can’t mindlessly rely on calculators all the time, as they do malfunction from time to time. While you may think that the formula for calculating the steel round bar weight is fairly simple (D2 / 162.2), it is not.
First of all, you should follow the manufacturer’s chart to calculate the weight. Second, there is no exact formula for calculating the weight of steel round bars, no matter how ridiculous it may sound.
You may wonder how that’s possible, as there are many websites offering different formulas for calculating the steel round bar weight. But the keyword, in this case, is “different.” They offer you different formulas. Basically, using one formula would give you one result, and using another formula would provide you with different results. So, regardless of which formula you use, you are most likely to get only approximate results.
So, does it mean that you are left without any formulas for calculating round bar weight? Well, not exactly. There are a few ways to calculate the weight, and we will provide you with them. All you have to do is to pick and choose the one you like the best.
1. The most common formula
The most common formula requires you to know the density of a squared inch. According to the formula, you can calculate the weight of the round bar this way:
Diameter in inches squared x 2.67 = lbs per foot.
2. D2 / 162.2
While this formula can be applied to calculate the round bar weight, it is generally used to calculate the weight of circular rebars. It is the formula for unit weight of steel. To use it, you need to figure out the derivation of D2 / 162.2, which you can see below:
Weight of steel bar per meter = Area of the steel x Density of steel x Bar length
= (3.14 x D2 /4) x 7850 kg/m3 x 1m
= (D2 x 6162.25)/(1000 x 1000)
= D2 X (0.006162)
= D2 X 1/(0.006162)-1
= D2/162.28
3. Experimental method
You can’t avoid experimental methods when there is no ultimate formula for calculating bar weight. So, to calculate it using the experimental method, you should follow the next steps:
- take a sample length of a steel bar (let it be one foot)
- take a pipe of the same length but with the larger diameter so that the bar would fit in it
- fill the pipe with water up to the top
- immerse the bar into the pipe
- then remove the bar from the pipe and fill the pipe once again with water
- now, we can state that the volume of water in the pipe equals the volume of the water that can be placed in the bar
Basically, it is Archimedes’ theory that we all learned in school.
