Which tool is NOT used to remove the rivet shank?

The correct choice indicates that a wrench is not used to remove the rivet shank, which is true. In the context of rivet removal, specific tools are designed to effectively deal with the rivet's physical structure.

A hammer is typically used in conjunction with other tools to deliver the necessary force to drive a punch through the rivet. The pin punch is specifically designed to drive out the rivet shank by inserting it into the hollow end of the rivet and applying force. A bucking bar is used on the opposite side of the rivet to support the material while the rivet is being driven out; it absorbs the recoil and provides a stable surface.

In contrast, a wrench is primarily designed for gripping, turning, and applying torque to fasteners with a hexagonal or square shape, such as bolts or nuts. It does not have the function or design needed to remove rivets, making it the tool that does not fit within the context of rivet removal work. Understanding the specific roles of these tools is crucial for effective and safe aerospace assembly and maintenance practices.