When using a hand threader, which condition will likely result in damaged pipe threads?

Using a hand threader with dull or nicked dies is likely to result in damaged pipe threads due to the inadequate cutting action of the dies when they are not sharp or have defects. Dull dies struggle to make clean cuts, which can lead to threads that are uneven, stripped, or improperly shaped; this can negatively affect the joint tightness and lead to potential leaks or failures.

In contrast, a properly maintained threader with sharp and clean dies would create smooth, precise threads, ensuring a good fit. While too much oil can cause excessive friction or slippage, it is not as directly damaging to the threads as utilizing worn-out cutting tools. Reaming a pipe helps ensure that it is free of sharp edges and obstructions, promoting better thread formation, but the failure to ream alone would not be as harmful as the effect resulting from using dull dies.