What type of wrench is used to tighten a socket head cap screw?

The hex wrench is specifically designed to engage with the hexagonal recess of a socket head cap screw. This type of screw features a hex socket that allows the wrench to fit snugly, providing the necessary leverage to tighten or loosen the fastener effectively. The design of the hex wrench allows for a good grip and torque application, making it suitable for use in situations where a socket head cap screw is present.

In contrast, a spanner wrench typically engages with fasteners that have a different shape, such as those with a round or notched external shape, and is not suitable for socket head cap screws. A ratcheting wrench is designed for quick, repetitive tightening or loosening of nut and bolt types that have an external grip, whereas a torque wrench is used for measuring the amount of torque applied to a fastener, rather than for directly interacting with its head. Thus, the hex wrench is the most appropriate choice for this type of screw.