Firefighter Exam 2025 – 400 Free Practice Questions to Pass the Test

The correct choice is the Allen wrench. This tool, often referred to as a hex key, is specifically designed with an L-shaped, hexagonal profile that allows it to fit snugly into the hexagonal recess of setscrews, which are commonly found in various mechanical applications. The unique shape provides excellent leverage, making it easier to tighten or loosen screws effectively.

In contrast, a torque wrench is used to apply a specific torque to a fastener and typically features a ratchet mechanism—this is not specifically suited for setscrews. The Stilson wrench is an adjustable pipe wrench designed primarily for gripping and turning pipes and fittings, which is not applicable for hexagonal fasteners. An offset wrench, while useful for accessing fasteners in tight spaces due to its angled design, does not have the hexagonal profile necessary to engage with setscrews. Therefore, the Allen wrench is uniquely suited for this task, addressing the specific need for gripping hexagonal screws.