Pliers for plumbing and mechanical work: tongue-and-groove, linesman, needle nose, diagonal cutters and specialty basin and strainer pliers.
Tongue-and-groove pliers are the plumber's default because the jaw stays parallel across the whole adjustment range, so the grip does not slip off a nut as the opening changes. Cheaper pliers lose that parallelism at the wide end and round off fittings.
On chrome and finished trim, use smooth-jaw pliers or tape the jaws. Serrated teeth will mark a visible escutcheon or supply nut permanently, and the mark shows up after the job is done rather than during it.
Handle length is leverage, not comfort. A 12" plier delivers noticeably more torque than an 8" on a seized fitting, but the shorter tool is the only one that fits under a vanity.
Brands include Milwaukee, Mill Rose, REED and J.C. Whitlam.
