Which action is necessary before replacing worn components of a power tool?

Before replacing worn components of a power tool, it is essential to ensure that the tool is unplugged or powered down. This action is crucial for safety reasons. When a power tool is connected to a power source, there is a significant risk of accidental activation during maintenance, which could lead to serious injuries. By unplugging or powering down the tool, you eliminate the risk of electrical shock and unintended operation, creating a safer environment for handling the tool's components.

While checking the owner's manual can provide helpful guidance on replacement procedures, and consulting a supervisor may be a good practice in a work environment, these actions do not address the immediate safety concern. Cleaning the tool is also beneficial for maintenance, but it does not impact the safety factor necessary for replacing components. The priority must always be safety first, which is fulfilled by ensuring that the power tool is completely powered off.