What measurement accurately describes a 2 x 4 after it has been processed through a lumber mill?

The measurement that accurately describes a 2 x 4 after it has been processed through a lumber mill is 3-1/2 inches by 1-1/2 inches. When lumber is first cut to nominal sizes (like 2 inches by 4 inches), it undergoes a drying and planing process to make it smooth and more uniform. This processing results in a reduction of the dimensions.

Therefore, a 2 x 4 that is finished typically measures 3-1/2 inches wide and 1-1/2 inches thick. This sizing convention is important for builders and contractors as it ensures consistency and compatibility with other building materials.

Other measurements provided do not align with the standard dimensions of a processed 2 x 4, which is why they are not correct. Understanding these final dimensions is crucial for anyone in the construction industry, as it affects how lumber is used in framing, structural support, and other aspects of building projects.