Which tool is designed to apply even force on both sides of a fastener?

The tool designed to apply even force on both sides of a fastener is known as a torque wrench. This tool is essential in many applications, particularly in pipe fitting and mechanical assembly, where the precise application of torque is crucial to ensure a secure and leak-free connection.

A torque wrench allows the user to set a specific torque value, ensuring that the fastener is tightened evenly and to the correct specification. This prevents damage to both the fastener and the material being worked on, as overly tight fasteners can strip threads or fracture components. The design of a torque wrench ensures that the force applied is distributed evenly, which contributes to the integrity of the assembly.

While a striking wrench can deliver significant force, it does not have the precision to measure or control the amount of torque applied. Similarly, a ratchet is used for turning fasteners but lacks the ability to measure torque accurately. A slotted screwdriver is primarily used for turning screws and does not apply torque in the same way as a torque wrench.

In summary, the torque wrench is specifically designed for the controlled and even application of force on fasteners, making it the correct choice in this context.