What role does the contact tube serve in MIG welding?

The contact tube plays a critical role in MIG welding by transferring electrical current to the continuous electrode. This component is essential because the electrode needs a consistent supply of electrical energy to generate the arc required for welding. When the welding machine initiates the process, the contact tube ensures that electric current flows smoothly from the power source through the consumable electrode wire and into the weld pool. This flow of current creates the heat necessary to melt both the electrode and the base materials, allowing for proper fusion.

The effectiveness of this process is heavily reliant on the contact tube's design and positioning, which must ensure a close connection without causing interference or arc instability. A well-functioning contact tube allows the user to maintain a stable arc, contributing to the overall quality of the weld.