MMA electrodes are identified by classification numbers that indicate their properties and intended use: 6013 is an easy general-purpose electrode, 7018 is a high-strength low-hydrogen electrode, 6010 gives deep penetration for pipe roots, and 7016 is a low-hydrogen electrode prized for impact toughness. Choosing the right classification is the single most important decision in MMA welding.
This guide explains each of the common electrode classifications and the key differences between them.
What is a 6013 electrode?
A 6013 electrode is one of the most popular general-purpose MMA electrodes. It produces a smooth arc, easy slag removal and an attractive weld appearance. 6013 electrodes are commonly used for mild steel fabrication, maintenance and repair work where ease of use is important.
It is a rutile electrode, which is what makes it so easy to strike and forgiving to use.
What is a 7018 electrode?
7018 is a low-hydrogen electrode designed for high-strength structural welding. It provides excellent mechanical properties and reduced risk of hydrogen cracking. 7018 electrodes are widely used in structural steel, pressure vessels, bridges and coded welding applications.
Because they are low-hydrogen, 7018 electrodes need correct dry storage to perform as intended — see MMA electrode storage and drying.
What is the difference between 6013 and 7018 electrodes?
6013 electrodes are easy to use and suitable for general fabrication. 7018 electrodes provide higher strength and lower hydrogen content, making them suitable for structural and critical applications.
For coded welding and heavy structural work, 7018 is often the preferred choice. For everyday mild steel fabrication where ease of use matters most, 6013 is usually the better pick.
What is a 6010 electrode?
6010 electrodes provide deep penetration and are commonly used for root passes on pipe welding and heavy structural applications. They are designed primarily for DC welding and perform well on dirty or coated steel. They are widely used in pipeline construction and repair.
This deep-penetration characteristic is why 6010 is the classic choice for pipe root runs — see choosing MMA electrodes by application.
What is a 7016 electrode?
7016 is a low-hydrogen electrode similar to 7018 but with different coating characteristics. It produces strong welds with excellent impact properties and is commonly used for structural steel fabrication. As with all low-hydrogen electrodes, proper storage is essential to maintain low hydrogen levels.
Quick comparison
| Electrode | Type | Typical use |
|---|---|---|
| 6013 | Rutile, general-purpose | Mild steel fabrication, maintenance, repair |
| 7018 | Low-hydrogen | Structural steel, pressure vessels, bridges, coded welding |
| 6010 | Deep penetration (DC) | Pipe root passes, heavy structural, dirty/coated steel |
| 7016 | Low-hydrogen | Structural steel; excellent impact properties |
[VERIFY: confirm the meaning of each digit in the AWS A5.1 classification system (e.g. tensile strength, welding position, coating/current) before publishing any breakdown of what the numbers mean — the source Q&As do not define them.]