#5 CSK Self Tapping Screw Zinc Plated

These screws are designed to create their own threads in materials like wood, plastic, or metal when driven in. However, they do require a pre-drilled pilot hole, especially in harder materials. The screw cuts threads as it’s driven in, allowing for a secure fit. They’re often used when you need a strong hold in softer materials.

#5 is the screw gauge size, which is approximately 0.125 inches (3.18mm)