Which fastener is best suited for securing two pieces of wood at a 90-degree angle?

Using a screw to secure two pieces of wood at a 90-degree angle is advantageous because screws provide superior holding strength compared to other fasteners. The threaded nature of a screw allows it to grip into the wood fibers more effectively, creating a strong connection that resists pulling apart. This is particularly important in applications where joints may experience lateral forces or separation over time, as the screw's design helps to maintain the integrity of the joint.

Screws also allow for better adjustment and alignment during the assembly process, as they can be driven in strategically to ensure a snug fit. If adjustments or disassembly are needed in the future, screws can be easily removed and reinserted without damaging the wood.

While nails and staples do provide some fastening ability, they lack the same level of grip and are more suitable for applications where sheer strength is not as crucial. Bolts can indeed provide strong connections, but they typically require additional hardware such as nuts and washers, making them more complicated for simple 90-degree joints. In summary, screws are the optimal choice for securely fastening wood joints at a right angle due to their holding power and ease of use.