What tool is used for tightening pipe fittings?

A pipe wrench or adjustable wrench is specifically designed to grasp and turn cylindrical objects, making it ideal for tightening pipe fittings. These tools have serrated jaws that provide a strong grip on the surface of the pipe, allowing for torque application without slipping. The design of the pipe wrench enables users to securely hold the pipe while tightening or loosening fittings, which is critical in plumbing applications to prevent leaks and ensure a proper seal.

Using a hammer, screwdriver, or socket set would not be effective for this purpose. Hammers are typically used for driving fasteners or breaking things apart, while screwdrivers are intended for turning screws, not for gripping or turning pipes. Although a socket set can be used on certain types of fittings, it lacks the necessary design features for gripping round pipes securely, making a pipe wrench or adjustable wrench the most suitable and effective choice for this task.