These metric screws have a triangular shank that presses tightly as it forms threads, so screws resist loosening in soft metals such as brass, aluminum, and copper.

Also known as Tap-Flex screws, these are made from hardened steel to penetrate hard material. They have a five-edged shank that presses tightly against the material to form threads and resist loosening.

Cutting their own pilot hole and threads as you fasten them into material, these metric screws have a drilling tip.