Bar Breaking Thermal Expansion and Contraction Apparatus

The Bar Breaking Apparatus demonstrates the forces involved in thermal expansion and contraction of metals. A long steel rod is mounted in a heavy iron frame, with one end drilled to hold a thin, brittle iron rod and the opposite end threaded with a knurled tensioning knob. When heated with a Bunsen burner, the steel rod expands and its tension decreases. The initial tension is restored using the knurled knob. As the rod cools, tension increases until the force on the smaller iron rod causes it to fracture, clearly demonstrating the forces involved in thermal contraction. The bar measures 13" long, and the base measures 12.75" long and 3.25" wide. Heating source and Bunsen burner are not included.