Why is it best to use a screwdriver with a square shank?

Using a screwdriver with a square shank is particularly advantageous because it allows for the use of a wrench to turn the screwdriver. This feature is valuable in situations where additional torque is needed to drive the screw into tougher materials or to dislodge a screw that is seized. The square shank design provides a greater surface area for the wrench to grip compared to other shapes, enabling more force to be applied without slipping.

This is especially useful in industrial or heavy-duty applications where screws may be set deeply or require significant force to install or remove. The ability to utilize a wrench enhances the functional versatility of the screwdriver, making it a preferred choice for many skilled workers in the field.