To make a joint leakproof with a screwed fitting on teflon-covered threads, how far must it be tightened?

The correct answer involves tightening the joint to the point of being hand tight with an additional 1/4 to 1/2 turn when using teflon-covered threads. This technique is essential for ensuring a leakproof seal in plumbing applications.

Teflon tape, or thread seal tape, reduces friction and allows for a tight fit without excessive force that might damage the threads. The method of hand-tightening the fitting ensures that it’s snug enough to make contact but not so tight that it risks stripping the threads or damaging the tape. The added slight turn—within the range of 1/4 to 1/2 turn—creates the necessary compression to ensure that the seal holds under pressure without risking leaks.

Choosing to tighten just to hand tight could leave the joint insufficiently sealed, while tighter options, such as two full turns, might over-compress the joint. Additionally, over-tightening can lead to cross-threading or potential failure of the fitting itself, due to too much force being applied. Thus, the specified tightening method balances adequate sealing with the integrity of the fittings and the longevity of the plumbing installation.