Belgium is a small country, but the coinage has proven to be one of the most common countries found in the mixed coinage by the pound that I like to purchase. I've gotten 54 coins from Belgium, ranking it well in the top 10 in most populous countries in my collection.
The frank is the most common, and in the mixed-by-the-pound I have built most of my collection through, I have gotten franks ranging in age from 1950 to 1995. I chose the 5 frank as the coin for this project solely because it scanned the best. The frank used the same obverse design.
Belgium is one of the countries now using the Euro, so they have abandoned the frank that had served them well since the 1830s.