Welding Processes: A Closer Look At SMAWFebruary 2, 2015
Perhaps the most fundamental of all welding processes is Shielded Metal Arc Welding (SMAW), also known as “stick welding.” This core welding method was developed over a hundred years ago and even today remains the most common form of arc welding. SMAW certainly has a number of excellent advantages that make it indispensable for many applications. However it also has some limitations that may make other welding processes a better choice for certain situations.
What Is SMAW?SMAW is a form of arc welding that uses a covered, consumable metal electrode to shield the weld. The electrode is covered in a flux coating that melts as the weld is laid, thereby releasing a vapor that protects the weld from atmospheric contamination. Because of the primacy of the metal electrode the term “stick welding” is often used to refer to SMAW. SMAW may utilize a variety of different sizes and types of electrodes depending on the particular application and other factors. The type and size of the electrode in turn affects the arc voltage requirements that will be needed, which may vary over a range of 16 to 40 volts. Similarly the amperage requirements for the weld may vary from as few as 20 amps all the way up to 550 amps. Either alternating current or direct current may be used depending on the electrode. In general larger electrodes are best suited for higher deposition rates and use higher currents. SMAW requires skill on the part of the welder in order to strike the arc, maintain the proper speed and angle, and make adjustments as necessary to optimize the weld. SMAW is often learned as the first welding process because many of the skills and proficiencies gained in SMAW will translate well to other welding processes. SMAW also remains one of the most trusted welding processes.
The Advantages of SMAWSMAW has many great advantages which make it a continuing staple in most industrial settings. These advantages include:
- Relatively simple equipment
- Most portable of all welding processes
- No need for separate gas shielding
- Can be used in a wide range of environments including outdoors, in fabrication shops, on pipelines and refineries, on ships and bridges, and more.
- Is not sensitive to wind and draft
- Well suited for a wide variety of commonly used metals and alloys
- Can be powered with gasoline or diesel in remote areas without electrical connections
- Equipment and knowledge of technique are already widely in place in most industrial settings
The Disadvantages of SMAWSMAW has some great advantages, but there are of course also disadvantages, which may not make it the best choice for certain projects. Some of the disadvantages include:
- Is not automated and thus usually has lower productivity rates than automated processes
- Deposition rates are typically lower than for other welding processes
- Requires more operator skill than many other processes
- Isn't suitable for metals that are reactive including: titanium, columbium, and zirconium
- May spatter and require extra cleanup.