How can I know if my 1 Cent coin from 1982 is of the KM #201, #201a or #201b ? I guess it cannot be the KM #201b as it haven't mintmark. But what are the differences? This is my coin:
You might be able to get a 12-inch ruler, center the 6-inch mark over some sort of fulcrum, put your 1982 cent at the one-inch mark and a pre-1982 cent at the 11-inch mark, and check to see which weighs more. Then, replace the pre-1982 cent with a post-1982 cent and repeat. You might be able to tell that your 1982 is about the same weight as one of the coins and definitely heavier or lighter than the other coin. The pre-1982 weigh 3.11 gm and the post-1982 weigh 2.5 gm.
yes, there is another way. (only for circulated coins, though) Get a pre-1982 cent and a post-1982 cent to compare with and then drop them onto a hard surface from about 1/4 meter and listen to the way the coins "ring" when they strike the surface. If the coin "rings" then it is MK 201 (and should sound the same as your pre-1982 comparison coin), but if it has a dull "clink" sound (and matches the sound of your post-1982 comparison coin) then it is KM 201a. BTW, 1982 US cents were issued with both the large and small date varieties, as well as in 2 different metal compositions and the pictured coin is the large date variety.
