If we want to assemble larger metal into a slightly too small hole we can use a technique called
a shrink fit.

For a shrink fit we are using the change in dimension that happens with a change in
temperature instead of just the brute force of a press fit. In our example of a larger peg and a
smaller hole, have a couple of options to consider:

We can heat the “hole” to enlarge it to the point it will accept the peg and then capture it when
everything cools down.

Or, we can cool the peg so that it contracts to fit the hole and again is captured when everything
returns to normal temperatures.

In either case, once everything is at the same temperature, the hole has a residual tensile stress
and the peg has a residual compressive stress.