The box joint pivot provides maximum support and strength. These pliers are suitable for both flat and pipe grip with an auto-tightening jaw grip. Strombergs, with their heat-treated heads, outlast others. Why are they called water pump pliers? Because they proved perfect for accessing hard-to-reach nuts and bolts, making them invaluable to auto mechanics working on engine water pumps. Hence their name. From their invention and manufacture in Illinois, these tools found widespread acceptance.