What is the breaking strength of a 4x4?

The breaking strength of a 4x4 piece of lumber can vary significantly based on the type of wood, its moisture content, and the specific conditions under which it is tested. For example, a dry, structurally graded 4x4 made of Douglas fir might have a bending strength of around 1,200 to 1,600 psi, while other species or conditions could yield different results. It's best to consult specific wood strength tables or standards for precise values.