For steel-to-steel connections, screws must extend through the steel a minimum of how many exposed threads?

The requirement for screws in steel-to-steel connections to have a minimum of three exposed threads relates to ensuring the integrity and security of the connection. When screws are installed, having a sufficient number of exposed threads guarantees that there is adequate engagement of the screw with the base material, which is crucial for achieving maximum holding strength.

In structural applications, especially in steel construction, the threaded portion of a screw plays a vital role in transferring loads and resisting shear forces. By requiring three exposed threads, the standard provides assurance that the screw is sufficiently embedded within the steel to perform its intended function without the risk of pullout or failure under stress.

This standard not only enhances the mechanical performance of the connection but also contributes to the overall stability and safety of the structure being constructed. Adhering to this requirement is critical in ensuring that the structural elements behave as intended under various load conditions.