The shift to copper-plated steel for this type reflects Nigeria's broader coinage reforms of the early 1990s, driven by rising base metal costs and a structural adjustment program that was reshaping the country's fiscal architecture. The older nickel-brass 25 Kobo had become too expensive to produce relative to its face value — a familiar problem for low-denomination coinage in economies under currency stress.
The shift to copper-plated steel for this type reflects Nigeria's broader coinage reforms of the early 1990s, driven by rising base metal costs and a structural adjustment program that was reshaping the country's fiscal architecture. The older nickel-brass 25 Kobo had become too expensive to produce relative to its face value — a familiar problem for low-denomination coinage in economies under currency stress.