Copper and Iron Compound Bar for Thermal Expansion

The Eisco Labs Compound Bar consists of copper and iron strips (each 200 × 15mm) riveted together. When heated, the bar bends due to the different thermal expansion rates of the two metals. This simple apparatus demonstrates the principle of differential thermal expansion — a fundamental concept in thermodynamics and materials science. The visual bending provides a clear, memorable demonstration. Suitable for physics classrooms.