The shift to copper plated steel for Trinidad and Tobago's five-cent piece was driven by the same commodity economics that pushed dozens of issuing authorities away from solid copper and bronze alloys in the late twentieth and early twenty-first centuries — the metal value of older coins was creeping uncomfortably close to face value. The magnetic property is strictly a byproduct of the steel core, useful for automated coin sorting but not an engineering goal in itself.
The shift to copper plated steel for Trinidad and Tobago's five-cent piece was driven by the same commodity economics that pushed dozens of issuing authorities away from solid copper and bronze alloys in the late twentieth and early twenty-first centuries — the metal value of older coins was creeping uncomfortably close to face value. The magnetic property is strictly a byproduct of the steel core, useful for automated coin sorting but not an engineering goal in itself.