What device controls the depth that a hole can be drilled?

The device that controls the depth a hole can be drilled is known as a depth stop. This mechanism is often an adjustable component found on drill presses or power drills, allowing the operator to set the maximum depth that the drill bit can penetrate. By using a depth stop, the operator can ensure consistent hole depths across multiple drilling operations, which is crucial in aerospace assembly where precision is paramount.

In contrast, the other choices serve different purposes. A chuck key is utilized to tighten or loosen the chuck that holds the drill bit in place but does not influence drilling depth. A clamp primarily secures the workpiece in position during drilling, ensuring stability but again does not affect depth. A drill guide can assist in maintaining drill bit alignment and can help achieve certain depth; however, it does not function as a dedicated mechanism to specifically limit or stop drilling depth like a depth stop does. Hence, the depth stop is the correct answer for controlling how deep a hole can be drilled.