Water pump pliers (also known as groove-joint pliers or tongue-and-groove pliers) are versatile adjustable hand tools designed for gripping, turning, and clamping irregularly shaped objects, nuts, bolts, and pipe fittings. Forged from high-grade chrome-vanadium steel, they feature hardened serrated jaws angled at roughly 45 degrees relative to the handles, providing exceptional torque and leverage in tight workspaces. Key structural features include a multi-position sliding pivot joint with machined tracking grooves for quick jaw width adjustment, self-locking jaw geometry that prevents slipping off workpieces, and long handles wrapped in dip-molded anti-slip rubber sleeves to maximize grip comfort and control. They are essential for plumbing, automotive, and general repair tasks.