The ridges on the sides of coins, also known as reeding or milling, serve several purposes:
1. Enhanced Security: The ridges make it more difficult to produce counterfeit coins, as they require specialized equipment and techniques to replicate accurately. Counterfeiters often lack access to such equipment, making it easier to detect and prevent the circulation of fake coins.
2. Distinctive Identification: The ridges create a distinct visual and tactile feature that helps people easily identify and differentiate between genuine coins and potential counterfeits. This is particularly important for visually impaired individuals who rely on touch to distinguish between coins.
3. Coin Stacking and Handling: The ridges provide a better grip and facilitate stacking of coins, making it easier to handle and count large quantities. They also help prevent coins from sticking together, especially in humid environments.
4. Authenticity Verification: The presence and quality of ridges are often used as a security feature by mints and governments. Irregularities or inconsistencies in the ridges can indicate potential counterfeiting.
5. Aesthetics and Design: In addition to their security and functional benefits, the ridges can add an aesthetic element to coins, enhancing their overall design and appearance.
It's important to note that not all coins have ridges, and the design of the ridges may vary across different countries and currencies. Nevertheless, the ridges play a crucial role in safeguarding the integrity and security of coins, making them an integral part of currency production.