The only hand tools that should be used on gas turbine engines are chrome plated, nickel plated, or which of the following?

Correct Answer: Option B — Unplated

Unplated tools are mandated to prevent hydrogen embrittlement and the risk of plating material flaking off into the engine. Any loose plating acts as foreign object debris (FOD), which can cause severe damage to high-speed rotating components or block cooling passages, compromising the structural integrity of the gas turbine.