A waterproof screw is a type of screw designed to prevent water from seeping through the gaps between the screw and the material it's screwed into. These screws are commonly used in outdoor applications where they will be exposed to rain, snow, or other forms of moisture.

Waterproof screws are typically made from materials that are resistant to rust and corrosion, such as stainless steel or coated steel. The threads of the screw may also be coated with a waterproof sealant to further prevent water from penetrating.

When selecting a waterproof screw, it's important to choose one that is appropriate for the specific application. Factors such as the type of material being screwed into, the size and length of the screw, and the level of moisture exposure should all be taken into consideration.

To make a waterproof screw not leak, you can follow these steps:

Use a waterproof screw: Make sure that the screw you are using is specifically designed to be waterproof.

Apply sealant: Apply a waterproof sealant, such as silicone or polyurethane, to the threads of the screw. This will prevent water from seeping through the gaps between the screw and the material it's screwed into.

Tighten the screw properly: Make sure to tighten the screw to the appropriate torque specification. Over-tightening can damage the sealant and cause leaks, while under-tightening can cause the screw to loosen over time.

Test for leaks: After the sealant has fully cured, test for leaks by spraying the area with water or using a hose to simulate rainfall. Check for any signs of water penetration and reapply sealant if necessary.

By following these steps, you can ensure that your waterproof screw does not leak and provides a secure, water-resistant seal.