What type of bolt has a hole drilled through its shank?

The type of bolt that has a hole drilled through its shank is referred to as a drilled bolt. This design feature allows for a safety wire or pin to be passed through the bolt, which can be extremely beneficial in applications where maximum safety and security are required. The drilled hole helps prevent loosening due to vibration or movement, making drilled bolts particularly useful in high-stress environments, such as in aviation or military applications where reliability is critical.

In contrast, other types of bolts, such as hex bolts, carriage bolts, and shoulder bolts, do not have this drilled feature. Hex bolts typically have a hexagonal head and are used in various fastening applications, while carriage bolts are mainly characterized by a round head and a square section underneath that prevents rotation when tightened. Shoulder bolts have a distinct shoulder that acts as a bearing surface but do not incorporate a drilled hole for safety fastening. This distinction underscores the unique functionality of drilled bolts in ensuring secure connections in critical applications.