For Round Bars. Rule : Multiply the square of the diameter in inches by the length in feet, and that product by 2.6. The product will be the weight in pounds, nearly.

For Square and Flat Bars. Rule : Multiply the area of the end of the bar in inches by the length in feet, and that by 3.32. The product will be the weight in pounds, nearly.

Wrought Iron, usually assumed:

A cubic foot=480 lbs.

A square foot, 1 inch thick= 40 lbs

A bar 1 in. square, 1 foot long = 3.5 lbs

A 1 yard long = 10 lbs

To find the weight of Cast Iron Balls when the diameter is given.

Rule: Multiply the cube of the diameter by 1.377

To find the diameter of Cast-Iron Balls when the weight is given.

Rule: Multiply the cube root of the weight by 1.936.

To find the weight of a Spherical Shell.

From the weight of a ball of the outer diameter subtract the weight of the inner diameters.