The design of tek screws is one of their most appealing aspects. Generally, they have a hex, torx, or slotted head, which facilitates easy application using power tools. The self-drilling tip is sharp, which allows it to penetrate materials without requiring an additional drill bit. Furthermore, the threading on a tek screw is optimized for a variety of materials, including metal, wood, and plastics, enabling it to secure different substrates firmly.

The functionality of metal expansion nuts centers around the principle of mechanical expansion. Upon the application of torque, the screw or bolt is threaded into the nut, which, in turn, causes the nut to expand outward. This outward expansion presses the sides of the nut against the inner walls of the hole it occupies, creating a tight fit. The added friction and mechanical grip prevent the nut from loosening over time, even in dynamic conditions.