The structural integrity of a wooden container is compromised when nailing into which part of the wood?

Nailing into the end grain of wood compromises the structural integrity of a wooden container because the end grain has limited holding power compared to the other grain orientations. When nails are driven into the end grain, they do not engage the wood fibers as effectively as they do when driven into the face or side grain. This results in a weaker connection that can easily pull out under stress or load.

In contrast, the face grain and side grain provide better resistance to withdrawal forces because the nails are aligned with the long wood fibers, allowing for a much stronger grip. Additionally, heartwood is the dense, inner part of a tree that provides strength and stability, but it is not relevant to the structural integrity compromised specifically by nailing into end grain. Thus, understanding the characteristics of different grain orientations is essential for ensuring the strength and durability of wooden structures.