- 19th Century and Early 20th Century: Pennies minted from the 19th century until 1982 were primarily composed of copper (95%) with a small amount of tin and zinc.
- 1982 to Present: After 1982, pennies were produced using a zinc core plated with copper. This change aimed to reduce material costs and preserve the coin's distinctive appearance while making them lighter.
2. Weight and Size:
- 19th Century and Early 20th Century: The copper pennies of this era were heavier and thicker due to their solid composition. They weighed approximately 4.67 grams and had a diameter of about 19.05 millimeters.
- 1982 to Present: With the introduction of the copper-plated zinc pennies in 1982, the weight of the coins decreased to 2.5 grams, making them lighter and easier to handle. The size remained largely unchanged.
3. Minting Process:
- 19th Century: Pennies during this time were primarily produced using a process called "striking." In this method, a metal blank is placed between two dies, which are then struck with force, imprinting the coin's design.
- 20th Century (post-1940s): An improved minting technique known as "upset forging" was introduced during the 20th century. This method involved forging a small metal slug and then placing it in a collar with the coin's design before being stamped.
These changes in pennies over time were driven by factors such as economic considerations, durability, and advancements in minting technology.