Width in ¼ ins. X Thickness in 1/8 ins., or vice versa, / 10 X Length, ft. = Weight, lbs. cast iron.

For instance: to find the weight of a casting 3¼ ins. X 1 1/8 ins. X 2 ft. 6 ins. long.

13 X 9 / 10 = 11.7 X 2.5 = 29.25 lbs.

This rule is very useful, and can easily be remembered in the following form.

Width in ¼ ins. X Thickness in 1/8 ins. or vice versa, cut off 1 figure for decimal, the result is lbs. per foot of length.

For wrought iron add 1/20th to the result; for lead add J; for brass add 1/7 th; for copper add 1/5 th.