Calculation equation for weighting copper and aluminum

I use this:

http://www.metalsuppliersonline.com/research/FreeWeightCalc.asp

It will calculate most metals (copper and aluminium included) in many shapes: sheet, bar, tube, angles etc.

weight = density of the material by its volume

kg = kg/m^3 x m^3

Weight, Kg = (Volume, m³) x (Density, Kg/m³)

Volume of tube = (Tube Cross Sectional Area, m²) x (Tube Length, m) = (3.14/4)(D_o² -D_i²) x (L)

So, Weight in Kg = (3.14/4) x (D_o² -D_i²) in m² x (L in m) x (Density in Kg/ m³)

where, Kg = Kilogram & m = meter

D_o = Tube Outside Diameter, m

D_i = Tube Inside Diameter, m

L = Tube Total Length (Coil Length), m

Note. If you have a solid rod, the same equation shall be applied, taken into consideration that the inside diameter D_i = 0.

Dear Mohamed,

I will give you some thumb rules. to claculate the weight in Kilo grams, or Grams per meter length. based on this you can caliculate for the quantity you want.

All dimensions should be measured in mm. ( suould be converted into millimeters)

Specific gravity and density should be in grams/ cm3

Specific gravity will be varied for metal in specific . like Aluminium cast: 2.56 , Aluminium Wrought : 2.70, Aluminium EC grade wire = 2.703 like copper also you have to refer the Tables.

Thumb rule :

Area of any shape in Squre mm multiplied by Density in Grams/cm2 result is weight of that perticular shape per Kilometer length, normally wires will be caliculated per K.M basis , if it converts into weight per Std.Metre , the value should be devided by 1000.

Example : Aluminium wire of 2.59 mm and density : 2.703 gr/cm3

Weight = (Area * Density) : ((22/28)*(2.59*2.59))*2.703= 14.246kg/k.m = 14.246 grams/metre.

Example for Copper tube: OD= 50 mm, ID=40 mm and density 8.89 gr/cm3

Wight = (Area * Density) : ((22/28 )*((50*50)-(40*40))*8.89 = 6286.49 kg/k.m = 6.286kg/metre.

Example of Aluminium Fins stock Strip Width: 33 mm, thickness= .10 mm and density =2.7 gr/cm3

Wight = (Area * Density)= (33 * 0.10)*2.7= 8.91 Kg/Km = 8.91 grams/metre.

I hope this will give you a clarity on how to do quick calculations of metal weight.

Best regards,

Srinivas.K

Guest,

If you are in the manufacturing of air con coils and would like to do basic costings...well you have to start at the raw product in the case of the fin as when you punch the holes you get waste and the waste is part of the cost of the coil.

The sames applies to the copper tubing...do you get it in lengths or do you get it in coil/rolls...the same applies to waste....

we found that a waste of 5 % is the low and at times up tp 15 %.. so it was part of the calculation...

best

To find the weight(W) of any material calculate its volume in cubic centimetres (V) and multiply it by its density(D). ie., W=D*V

D in grams/cubic centimetre(gm/CC) for some common metals:

Cast Aluminium 2.56

Wrought Aluminium 2.70

Copper 8.89

Mild steel 7.85