Process Capabilities and Limitations:

Shielded metal arc welding is one of the most broadly used processes, specifically for short welds in maintenance, production and repair work, and for field construction. The following are advantages of this procedure :

1. The equipment is comparatively simple, inexpensive, and portable.

2. The covered electrode provides the filler metal and the means of defensive it and the weld metal from destructive oxidation during welding.

3. Auxiliary gas shielding or granular flux is not needed.

4. The procedure is less sensitive to wind and draft than gas shielded arc welding processes.

5. It can be used in areas of limited access.

6. The process is suitable for most of the commonly used metals and alloys.

 SMAW electrodes are available to low alloy steels and weld carbon, cast irons, stainless steels, copper, and nickel and their alloys, and for some of the aluminium applications. Low melting metals, such like lead, tin, and zinc, and their alloys, are not welded along SMAW because the intense heat of the arc is too high for them. SMAW is not appropriate for reactive metals such as zirconium, titanium ,tantalum, and columbium because the shielding provided is insufficient to prevent oxygen contamination of the weld.

Covered electrodes are generated in lengths of 230 to 460 mm. Since the arc is first struck, the current flows the whole length of the electrode. The amount of current that may be used hence is limited by the electrical resistance of the core wire. Excessive amperage overheats the electrode and breaks down the covering. It, in turn, changes the arc characteristics and the shielding that is achieved. Because of this limitation, deposition rates are usually lower than for a welding procedure such as GMAW.

Operator duty cycle and total deposition rates for covered electrodes are typically less than provided with a continuous electrode procedure such as FCAW. This is because electrodes might be consumed only to some certain minimum length. While that length has been attained, the welder ought to discard the unconsumed electrode stub and insert a new electrode in the holder .Additionally, slag usually ought to be removed at starts and stops and before depositing a weld bead next to or onto a previously deposited bead.