New 500 Yen Bi-Color Clad — World-Class Anti-Counterfeit Technology

The issuance of the new 500 yen coin in 2021 marked the third year of the Reiwa era. This year was underscored by the urgent need for innovation in anti-counterfeiting technology. Economic stagnation continuing from the Heisei era and global financial instability necessitated enhancing currency trustworthiness. Particularly, the 500 yen coin, being a high-value coin easily targeted for counterfeiting, required urgent measures. Thus, the Japanese government instructed the Mint Bureau to develop a new coin with unprecedented anti-counterfeiting technology. This was influenced by economic policy changes, such as the consumption tax increase in 2019. After the tax hike, the importance of cash transactions was reassessed, and ensuring the trustworthiness of coins became a political issue. In this context, the three-layer bi-color clad was chosen as the cutting-edge technology for anti-counterfeiting. This technology combines different metals to make counterfeiting extremely difficult. The introduction of bi-color clad technology was revolutionary in Japan's coin history, akin to the historical transformation brought by the Keichō Koban.

The minting of the new 500 yen coin was carried out at the Mint Bureau in Saitama Prefecture. The coin's most significant feature is its three-layer structure called bi-color clad. The outer part is made of cupronickel, and the inner part is a brass alloy, making counterfeiting extremely difficult. Cupronickel, an alloy of nickel and copper, is known for its durability and corrosion resistance. On the other hand, the brass alloy, a combination of copper and zinc, is noted for its workability and attractive luster. Combining these two metals resulted in a coin that balances aesthetics and functionality. Furthermore, the coin employs an irregular rim. This adds slanted reeding to the sides of the coin, enhancing its anti-counterfeiting effect. Also, the sides engrave micro-letters of "500円", a feature for anti-counterfeiting. These micro-letters can only be reproduced with specialized machinery, not accessible to typical counterfeiting methods. Thus, the new 500 yen coin is the culmination of multi-layered technologies, representing the summit of anti-counterfeiting technology unseen elsewhere in the world. The adoption of bi-color clad technology and irregular rims has modern-day innovation compared with historical coinage technologies like those seen in the Edo Silver Coin.

The new 500 yen coin, which began circulation in 2021, quickly spread nationwide. Initially, its varying design and functionality sparked discussions among consumers and shops. The coins, incorporating new technologies such as irregular rims and micro-letters, astonished many who encountered them for the first time. In some cases, vending machines and cash exchange machines were not equipped to handle the new coins, causing confusion, but adjustments were rapidly made. The improved anti-counterfeiting technology enhanced the reliability of currency transactions, prompting a resurgence of cash transactions and stimulating consumer activity. Particularly in local shops, the assurance of cash safety led to increased economic activities. For coin collectors, too, the new 500 yen coin became a subject of interest. Its amalgamated technologies make it highly collectible, frequently featured in Basic Knowledge of Coin Auctions. Collectors across the country are eagerly seeking to acquire the new 500 yen coin, and the market is expected to expand.

The appearance of the new 500 yen coin is expected to significantly influence Japanese currency in the future. The advanced anti-counterfeiting technologies adopted in this coin will serve as crucial benchmarks for future currency design. For instance, the bi-color clad technology might be applied to other coins, and similar technology is already being considered for some coins. Bi-color clad, composed of a three-layer structure of cupronickel and brass alloy, offers advanced anti-counterfeiting capabilities. Moreover, technologies such as irregular rims and micro-letters might be applied to other coins and banknotes, driving further progress in anti-counterfeiting efforts. The irregular rims feature serrations and slanted reeding, which, when combined, not only make it easily identifiable but also realize advanced anti-counterfeiting functions. The success of the new 500 yen coin is attracting international attention, with requests for technology provision coming from other countries' mints. For example, some European countries and Asian region mints aim to enhance their coin safety by referencing Japanese technology. This ensures Japanese minting technology is globally acknowledged. Furthermore, technologies from the new 500 yen coin are expected to be employed in issuing special coins like Types and Characteristics of Commemorative Coins. Thus, the new 500 yen coin emerges as more than just currency, signifying crucial indicators for future currency concepts. Although it does not incorporate an IC chip, the coin issued in Reiwa 3 (2021) realizes world-class anti-counterfeiting measures through the combination of materials and processing technology.