A tool includes a barrel, a guiding wire, and an electrically conductive member. The barrel is made of electrically conductive material. The guiding wire is disposed in the barrel. The barrel and the guiding wire are directly or indirectly connected to two opposite electrodes of a power source. The electrically conductive member is connected to an outer periphery of the guiding wire and is electrically connected to the guiding wire. The electrically conductive member is disposed between the barrel and the guiding wire and is spaced from the barrel. When the power source is activated, an electric arc is generated between the electrically conductive member and the barrel.