If you are a beginning welder, you might be overwhelmed by the sheer amount of welding electrodes that are out there. There are many different kinds of welding electrodes and they vary depending on what sort of task is needing to be done and how the electrode will affect the process of welding.
Electrodes are made to be used with a specific range and kind of electric current. You will find that welding electrodes all come in different sizes and with different coatings so that a welder will be able to find one that will meet any requirements they might have.
An electrode produces the current that a welder needs in order to do arc welding. Generally, electrodes are shaped like stable wires or long rods and they have a contact point at the tip that channels powerful electric current into metal. When you place the tip of the electrode near the metal you are to work on, the electrical current will jump into the metal. This creates the arc that arc welding gets its name from. It also makes the heat that will melt the metal so it can be manipulated.
Beginner welders should know about the ratings of electrodes. Welding electrodes are rated using a system that was designed by the American Welding Society. A letter, such as E, is followed by four or five numbers. The diameter is usually expressed in inches before the identification so the code would look something like 1/12th-inch E5101. This means the electrode is 1/12 of an inch in diameter and used in arc welding (according to the E). The numbers reveal what tensile strength the electrode has by the first two numbers and the last two show the coating the electrode has and the currents you can use it with. Other numbers are sometimes added to show even more information.
There's three kinds of welding electrodes. Consumable electrodes burn away slowly while you are using them. You will have to replace them at regular intervals. You purchase this kind of electrode in bulk and they are less expensive then the permanent kinds and they are easier to use but don't have a lot of commercial uses. You don't always need to use gas with these because of the gases produced in the burning process.
Another kind is flux. These are consumable electrodes coated with chemicals (the flux). The coatings create a smoother and more protected weld. When the flux burns, a small cloud of gas is made that shields the weld area from oxygen and contaminants, giving you a cleaner weld and smoother cooling process. The metal will also burn and gets added to the weld, which helps with stability. You can choose from many different kinds of flux coatings. Each one has slightly different effects.
Non-consumable electrodes channel the electric current and last for a long time. Tungsten rods are one kind of non-consumable electrode. Electrodes that are non-consumable are considered to be more difficult to use and you have to remember that you need to use a shielding gas when you use this kind of electrode. The gas can be any of several different kinds of compounds and the gas is spread around the site of the weld. It performs the same kind of protection that flux does. You can use non-consumable welding electrodes in a wide variety of metals, including heavy metals, and these have a wider variety of uses than consumable electrodes do.
There's a lot of information for beginning welders to take in, and knowing the different kinds of welding electrodes will help any welder greatly in their career.