Which component is designed to break away on a Hi-Lok when the specified torque is reached?

The correct answer is the wrenching device. In a Hi-Lok fastener, the wrenching device is specifically designed to break away at a predetermined torque level during installation. This feature ensures that the fastener is properly tightened without exceeding the torque specifications, which could lead to mechanical failure or damage to the assembly.

When the specified torque is reached, the locking mechanism within the Hi-Lok prevents any further tightening, thus maintaining the integrity of the connection and ensuring consistent performance. Understanding this function is crucial for aerospace mechanics, as it directly impacts the reliability and safety of aircraft structures.

The other components mentioned have different roles. The locking collar engages with the fastener to secure it in place but does not serve the purpose of breaking away at torque. The fastener head is involved in the overall operation but does not break; instead, it remains intact as part of the assembly. The grip length refers to the section of the fastener that engages with the material being fastened but is not the component responsible for breaking under torque.