cobalt round bar weight calculator

Enter the dimensions of a cobalt round bar and this works out its volume and weight. Pure cobalt.

Diameter

Length

Number of pieces

Total weight

4.368 78kg

≈ Rounded cobalt round bar weight Show in

Weight of one round bar: 4.368 78
Volume of one piece: 490.874
Weight per metre of length: 4.368 78 kg/m
Density used: 8900 kg/m3

Show the working

Diameter = 25
Length = 1000
Number of pieces = 1
volume_mm3 = pi * (25/2)^2 * 1000 = 490 874
Volume of one piece = 490 874 / 1000 = 490.874
Density used = 8900 = 8900
Weight of one round bar = 490 874 * 8900 / 1e9 = 4.368 78
Total weight = 4.368 78 * 1 = 4.368 78
Weight per metre of length = 490 874 / 1000 * 1000 * 8900 / 1e9 = 4.368 78

Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.

Scenarios & local history

Compare a saved scenario

Recent calculations

The formula

Volume = pi x (diameter / 2)^2 x length
Weight = volume x density, with density = 8900 kg/m3
One cubic millimetre of a material at 1000 kg/m3 weighs exactly one milligram, so the millimetre-to-kilogram step is a shift of the decimal point rather than a rounded factor.

Pure cobalt.

Dimensions are nominal. Mill tolerances on thickness, and the corner radii on formed sections, both move the real weight by a percent or two.

Every field takes inches or feet as readily as millimetres: change the unit next to it and the conversion is done exactly before the arithmetic starts.

Frequently asked

What is the density of cobalt?

8900 kg/m3, which is 8.900 g/cm3. Pure cobalt.

How do you calculate the weight of a cobalt round bar?

Volume = pi x (diameter / 2)^2 x length. Multiply the volume by the density of cobalt, 8900 kg/m3, taking care that both are in the same unit system.

Can I enter dimensions in inches?

Yes. Each dimension field has its own unit selector, and inch, foot, millimetre, centimetre and metre entries are all converted exactly before anything is multiplied.

Where the numbers come from

Densities are nominal room-temperature values for the grade named, drawn from the usual mill and handbook figures.