What is the last number of the electrodes that run on DC positive?

The last numbers of electrodes that run on direct current (DC) positive polarity are indeed 5 and 0. This refers to the classifications of electrodes in the American Welding Society (AWS) specification.

Electrodes that are characterized by the last numbers 5 or 0 indicate that they are designed to be used effectively in DC positive polarity situations. Using electrodes with this specification allows for good arc stability and helps in achieving deeper penetration, which is crucial in various welding applications.

This characteristic of polarity is important for welders to understand, as it affects the performance and quality of the weld. When using DC positive, the electron flow moves from the electrode to the workpiece, providing a different heat concentration and metal transfer properties compared to other polarities. Understanding this helps ensure the right equipment and electrodes are employed for specific welding tasks, resulting in stronger and more reliable welds.