Plasma cutting power sources and welding machines

Shielded metal arc welding (SMAW), also known as manual metal arc (MMA) welding, flux shielded arc welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode coated in flux to lay the weld. It’s the process more suitable for outdoor use (and then on site) since it does not require the shielding gas. An electric current, in the form of either alternating current or direct current from a welding power source, is used to form an electric arc between the electrode and the metals to be joined. As the weld is laid, the flux coating of the electrode disintegrates, giving off vapours that serve as a shielding gas and providing a layer of slag, both of which protect the weld area from atmospheric contamination as it solidifies. Once hardened, it must be chipped away to reveal the finished weld. As welding progresses and the electrode melts, the welder must periodically stop welding to remove the remaining electrode stub and insert a new electrode into the electrode holder. This activity, combined with chipping away the slag, reduce the amount of time that the welder can spend laying the weld, making SMAW one of the least efficient welding processes.
Because of its versatility and simplicity shielded metal arc welding is one of the world's most popular welding processes, it is particularly dominant in the maintenance and repair industry, and is heavily used in the construction of steel structures and in industrial fabrication. In recent years its use has declined in favour of other types of welding. However, because of the low equipment cost and wide applicability, the process will likely remain popular, especially among amateurs and small businesses.
The choice of electrode for SMAW is wide and depends on a number of factors, including the weld material, welding position and the desired weld properties.
MMA welding equipment typically consists of a welding power source, electrodes, an electrode holder, a ground clamp and welding cables.