How do you choose the right electrode for SMAW?

1 Electrode classification

To choose the right electrode for SMAW, it is important to understand the electrode classification system used by the American Welding Society (AWS). This code consists of four or five digits, followed by a dash and a letter or a letter and a number. For instance, E6010 indicates an electrode for arc welding with a minimum tensile strength of 60 ksi in all positions, with a coating type and current type of 0 (cellulose sodium, DC+). An optional suffix can be added for additional requirements such as impact strength or diffusible hydrogen content.

2 Base metal

The second step to choose the right electrode for SMAW is to match the electrode with the base metal. The electrode should have similar or higher strength than the base metal to avoid cracking or failure of the weld. The electrode should also have compatible chemical composition and metallurgical properties with the base metal to avoid corrosion or embrittlement. For example, if you are welding carbon steel, you can use electrodes with mild steel core, such as E6010, E6011, E6013, or E7018. If you are welding stainless steel, you should use electrodes with stainless steel core, such as E308, E309, or E316. If you are welding cast iron, you should use electrodes with nickel or nickel-iron core, such as ENi-CI or ENiFe-CI.

3 Welding position

The third step to choose the right electrode for SMAW is to consider the welding position. The welding position refers to the orientation of the weld joint and the direction of the weld bead. There are four basic welding positions: flat, horizontal, vertical, and overhead. The welding position affects the fluidity and penetration of the weld pool, as well as the slag removal and arc stability. Therefore, you should select an electrode that can handle the gravity and arc force in different positions. For example, if you are welding in all positions, you should use electrodes with fast-freezing slag, such as E6010, E6011, or E7018. If you are welding in flat and horizontal positions only, you can use electrodes with slower-freezing slag, such as E6012, E6013, or E7024.

4 Current type

The fourth and final step to choose the right electrode for SMAW is to determine the current type. The current type refers to the polarity and the waveform of the electric current that flows through the electrode and the workpiece. There are two main types of current: direct current (DC) and alternating current (AC). DC has a constant polarity, either positive (DC+) or negative (DC-), while AC alternates between positive and negative polarity at a certain frequency. The current type affects the heat input, arc stability, penetration depth, and spatter level of the weld. Therefore, you should select an electrode that can perform well with the current type that you have available or prefer. For example, if you have a DC power source, you can use electrodes that are designed for DC+, DC-, or both, such as E6010, E6011, E6013, E7018, or E7024. If you have an AC power source, you can use electrodes that are designed for AC or both, such as E6011, E6013, E7018, or E7024.

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?