IRON RODS.
To find the weight of round iron rods.
Divide the square of the diameter, in quarter inches, by 2, and the quotient will give the weight in pounds, per yard.
Example.—What is the weight of a yard of 1-inch round iron.
1 inch = 4 quarters 42 = 16 16 2 = 8 lb. Weight required.
To find the weight of square rods.
The weight of round rods, of similar diameter, divided by ·7854 will give the weight of the square rods.
To find the weight that may be sustained, or lifted by round iron rods.
Find the weight in pounds, per yard; two-thirds of which will give the safe load, in tons.
A round iron rod of average quality of iron, one inch in diameter, will be torn asunder by 16 tons; it will be perceptibly damaged by half this strain, or 8 tons; its safe load will be one-third, or 5·33 tons.