A pipe wrench is a heavy-duty adjustable hand tool specifically designed for turning, tightening, and loosening threaded smooth-surface iron pipes, fittings, and round metal stock. Built with a sturdy cast-iron or aluminum body, it features self-locking, deep-serrated steel jaws that bite firmly into cylindrical surfaces when force is applied in the direction of turn. Key design elements include a threaded floating hook jaw, a fixed heel jaw, an easy-turn knurled adjustment nut for smooth size calibration, and a long I-beam handle that provides substantial leverage while maintaining structural strength. It is an indispensable tool in plumbing, HVAC work, gas fitting, and industrial piping operations.