The 500 Yen “slug”

A Japanese 500-Yen coin (Showa 63, 1988) left, and a South Korean 500-Won coin with gouges drilled into its surface to approximate the weight of the Japanese 500-Yen coin. Hundreds of thousands of these “slugs” were found in Japanese vending and cash machines all across Japan in the late 1990s and early 2000s. The South Korean coin is approximately 1/10th the value of the Japanese coin.

Here’s a South Korean 500-Won coin (right) drilled to lighten it so that it approximates the weight of a Japanese 500 Yen coin (left). The 500-Yen coin is worth (current exchange rate) $4.85 in USD. The 500-Won coin is worth .44 cents.

Criminals used the 500-Won coin as “500-Yen” to obtain illegal profits by inserting these “slugs” into a Japanese vending machine and then pressing the “Coin Return” button. Japanese vending machines do not return the coin you put into the machine, but will drop a coin from the change hopper — a REAL 500-Yen coin (or 500 yen in other coins).

The Japan Mint Bureau changed the design and metal composition of the 500-Yen coin in 2001 in order to counteract this activity. These 500-Won coins were made into slugs and trafficked into Japan in the late 1990s to around 2001. It took years, though, for Japanese vending machines to be switched over to accepting the new, post-2001, 500-Yen coins only…