Water-pump (groove-joint) pliers
These are sometimes called "Groove Joint pliers," "Slide Grip pliers", or even "Alligator pliers," but us old-timers know them as Water-pump Pliers. The main reason you want them is to snug up dripping hose connections, but they're also useful for loosening other things when you don't have the appropriate wrench or holding something in place while you drill through it. I've also used them to get cranky caps off tubes of used glue.If you use quick connectors on your hoses, you might think you don't need these, but they're essential for screwing in the small adapters that are too small to get a good grip on with your hands.
Be careful using them on hose connections. If you squeeze too hard, you can crack plastic connectors or make brass connectors oval instead of round. The same goes for plastic caps on things like tubes of glue.
Water-pump pliers come in two main forms: straight-jaw and curved-jaw. The curved-jaw ones are best for turning things that are round, like hose connections. The straight-jaw ones can work better on rectangular of hexagonal objects. The ones above are kind of a compromise. The jaws have a straight section and an angled section so they work fairly well for anything.
Thank you for visiting BobsGuides.com
— Bob Ray