Welding Electrode Classifications

Welding electrodes are essential consumable components used in various welding techniques to facilitate the joining of metals. They conduct electrical current to produce an arc that melts and fuses the base materials. Understanding welding electrode classifications is essential for any welding professional or enthusiast looking to achieve optimal results in their projects. This blog will explore the different classifications of welding electrodes, highlighting their unique properties and applications.

What are Welding Electrodes?

Welding electrodes are crucial components in the welding process, serving as both a conductor of electricity and a filler material. Used for joining metal pieces, they create a stable arc between the electrode and the base metal to melt the material. A well-chosen electrode matched to the parent metal ensures efficacy and robustness.

Welding Electrodes Classification: Based On AWS (American Welding Society)

The classification of welding electrodes considers factors such as the electrode metal, flux coating, current used, welding position, performance characteristics, chemistry, and mechanical properties of the weld metal, among others.

The American Welding Society (AWS), the Bureau of Indian Standards (BIS), the British Standards Institution (BSI), the Deutsches Institut für Normung (DIN), and ISO 2560 are just a few of the organizations that have established standards for the nomenclature and classification of welding electrodes. 

The welding industry has embraced the classification number system of the American Welding Society. Standard welding electrodes for various uses are given numbers, including E6010, E6011, E6013, and E7018. For illustration, let's examine the electrode E6013, which is commonly used on board.

• E XXXX: In welding, the E in E6013 stands for flux-covered electrode. It is popular in manual arc welding.
• E60XX: The following two characters stand for the minimum tensile strength. The "60" in E6013 denotes a minimum tensile strength of 62000 psi for the metal used in the weld.
• EXX1X: The fourth character specifies how many positions this electrode can use for different welding processes. The "1" in E6013 in this example denotes that welding can be performed in a flat, above, horizontal, or vertical position (upwards). For other relevant numbers and the accompanying welding positions.
• EXXX3: This fifth character describes the kind of flux coating applied, the extent of the electrode penetration, and the kind of current appropriate for the electrode. In this instance, the "3" in E6013 indicates that the flux coating is based on rutile potassium. The electrode has low penetration and works with both AC and DC currents. For a list of more key numbers and their attributes.
• EXXXX-X: Sometimes, additional criteria call for using this additional character. For instance, the suffix "A1" in the last refers to adding 0.5% Mo to the electrode E7018-A1. Refer to the table below for more suffixes. Even though the electrodes may adhere to the same standard, these suffixes typically vary from manufacturer to manufacturer since each manufacturer likes to add a personal touch.

The electrode with the number E6013 printed on it is a rutile potassium-based flux-coated mild steel electrode with a minimum tensile strength of 62,000 psi and light penetration, that it can be utilized in all welding positions other than vertically down.

Read More: Types of Welding Electrodes

Welding Electrodes Classification: Based On ISO Standard

The ISO standard for classifying welding electrodes for manual metal arc welding is ISO 2560: 2009. All national, regional, and worldwide standards are based on this international standard. It provides far more information and is more thorough than the AWS classification; however, it is not as simple to remember and recall as the AWS classification.

For instance, ISO 2560 classification for a welding electrode is E55 3 MnMo B T 42 H10. It will cover the relevant numbers one at a time.

• E55 3 MnMo B T 42 H10: In this case, the letter "E" stands for a flux-covered electrode used in manual metal arc welding.
• E55 3MnMo Bt 42H10: The weld metal will have a minimum tensile strength of 550 N/mm2 according to the number 55. The other relevant numbers and their corresponding tensile strengths are listed in the table below.

• E55 3 MnMo B T 42 H10: The significant number "3" here denotes the lowest temperature below which the weld will become fragile. To be deemed non-brittle, a weld must withstand 46J energy without breaking. Thus, "3" here indicates that the weld will become brittle at or below -30 deg C.
• E55 3 MnMo B T 42 H10: This is a supplementary field that is occasionally populated. The alloy metal in the weld deposit is indicated by the letters "MnMo" in this case. In this specific instance, the critical character predicts that the weld deposit will contain molybdenum at a concentration of between 0.3 and 0.6% and manganese between 1.4 and 2.0%.
• E55 3MnMo Bt 42H10: The crucial letter "B" in this sentence represents the kind of flux coating. It is a basic covering made of calcium carbonate in this instance. Please see the table below for information on other types of flux coatings.

Read More: Metal Fabrication vs. Welding

• E55 3MnMo Bt 42H10: Here, the letter "T" adds additional guidance about the weld's heat treatment. The weld must be annealed to between 560 and 600 degrees Celsius for one hour, then cooled in a furnace to 300 degrees Celsius before being chilled in the air.
• E55 3 MnMo B T 42 H10: The crucial "4" in this sentence relates to the deposit and current rates. It has a deposit rate of 105 to 125% in this instance and may only be used for DC. The fact that it exceeds the amount of metal in the welding electrode indicates that there is some iron powder in the flux layer.
• E55 3MnMo Bt 42H10: The crucial number "2" in this sentence denotes the points at which the electrode may be utilized for welding. Here, it refers to all positions other than vertically downward.

• E55 3 MnMo B T 42 H10: The hydrogen content of the deposited welding metal is indicated by the symbol "H10" in this equation. It is 10ml/100g in this instance. To view additional symbols, please see the table below.

The label (E55 3 MnMo B T 42 H10) on a welding electrode indicates that it is a primary flux-coated welding electrode with a minimum tensile strength of 550N/mm2 that will become brittle at -30 degrees Celsius. It features a manganese alloying concentration of 1.4 to 2.0% and a molybdenum alloying concentration of 0.3 to 0.6%. It has a deposit rate of 105 and 125% and can operate with DC. You can use it in all positions except vertically down. The hydrogen content of the deposited welding metal will be 10 ml/100g. Therefore, the ISO 2560 standard is more thorough and detailed than AWS, but it is also tough to memorize without the correct specification tables.

Conclusion

Welding electrodes are essential for creating strong, reliable welds in various applications. Understanding the different classifications and their specific uses helps in selecting the right electrode for your project, ensuring optimal results. Proper choice and handling of electrodes not only improve weld quality but also enhance safety and efficiency in the welding process. Investing in the correct electrodes and mastering their use can lead to durable, high-quality welding.