How many screws are required for wood sections that are 150mm or less wide?

When securing wood sections that are 150mm or less in width, the requirement for using two screws is based on best practices for ensuring structural integrity and stability. Two screws provide sufficient holding power to resist forces such as shear and withdrawal, which are critical in preventing failure or movement of the joined sections.

Utilizing a single screw can lead to inadequate fastening, especially when dealing with varying conditions like load and movement, which can result in loosening or misalignment over time. On the other hand, increasing the number of screws beyond two for this width could be excessive and may not contribute significantly to the strength of the joint, while also risking damage to the material due to overcrowding of screw holes.

Therefore, using two screws for wood sections that are 150mm or less is the standard method to achieve a balance of strength and material integrity.