Which tool would you use for tightening small screw threads?

The Allen wrench is specifically designed for tightening small screw threads, particularly those with hexagonal sockets, commonly found in furniture assembly, bicycles, and various mechanical applications. Its unique shape allows it to fit perfectly into the screw’s recess, providing maximum torque without slipping, which is crucial for securely fastening screws. This makes the Allen wrench ideal for such tasks, enabling precise control and adjustment.

Other types of wrenches, such as the adjustable wrench, socket wrench, and standard wrench, are typically used for larger nuts and bolts or have a different operational style that is not as effective for the small, hex-headed screws that the Allen wrench is suited for. Therefore, the Allen wrench stands out as the best choice for this specific purpose.