Self-drilling screws for metal up to 3.5 mm thick require no pre-drilling, nuts, bolts, or spanners. There is no need to change drill driver bits, as they use a standard Pozidrive 2 recess. These screws can be removed and reused, making them ideal for electricians. They enable faster joining of cable trays, cable trunking, trunking lids, armored cable cleats, mounting din rail, and accessories in central control panels. They also provide quick fixing of earth tails to galvanized trunking boxes.