by PHXinArizona » Sun Nov 20, 2011 6:11 pm
It depends on the date of the penny. Lincoln pennies minted from 1909 to 1982 are 95% copper and weigh 3.11 grams each. (Except the 1943 steel pennies which weigh less)
In mid 1982 pennies were switched from being made mostly of copper to zinc with a very thin coating of copper. These zinc pennies (including ones made today) weigh 2.5 grams.
These weights are for pennies that are in new condition and haven't been worn down by lots of handling.
1000 grams = 1 kilogram
1 kilogram = 2.2 pounds
1000/2.2 = 454.54 grams to a pound
454.54/16 = approx. 28.41 grams per ounce (16 ounces = 1 pound)
3.11/28.41 = approx. 0.11 Weight in ounces of one pre-1982 Lincoln penny
2.5/28.41 = approx. 0.088 Weight in ounces of one post-1982 Lincoln penny
It would take approx. 146 pre-1982 pennies to equal one pound. (28.41/3.11 x 16)
And approx. 182 post-1982 pennies to equal one pound (28.41/2.5 x 16)
The composition of the Lincoln penny was changed in mid-1982. Some 1982's are copper, some are zinc. You would have to weigh each individually to determine without actually cutting into it to get the composition of the coin.