Final answer:
Use a tap drill bit sized appropriately for the desired thread to finish drill the hole before threading. Correct sizing is critical for thread accuracy and strength.
Step-by-step explanation:
To finish drill the hole to final size for threading, you would use a tap drill bit that corresponds to the size required for the intended thread. This bit is used after the initial hole has been created to ensure that the threads can be accurately cut to match the specifications of the tap that will be used subsequently. Determining the correct size of the tap drill bit is crucial because it directly influences the effectiveness of the threading process and the strength of the hold the thread will have.