I'd like to point out that, although it is illegal to put lead in water supply lines in the US, there is a loophole that allows it in hot water lines.
As a result, for certain fittings, most big-box hardware stores only sell the leaded variants, and label them "hot water heater supply line" or something similar.
As a result, for certain fittings, most big-box hardware stores only sell the leaded variants, and label them "hot water heater supply line" or something similar.