Observe how the metal tyre is fitted on the wheel of a bullock-cart.

● The increase in temperature causes the metal to expand hence the ring becomes large enough to perfectly fit on the wheel. . At this point the obvious happens, the wooden wheel starts to burn

● Now it is allowed to cool and the metal contracts as it cool, squishing the wheel tightly. The tyre shrinks back to its original size and tightens the wheel joints creating a strong and durable wheel.

● Now we have a metal tyre on the wheel of a bullock cart, which doesn't slide off.