Let’s dive right in with the basics. What is SMAW welding? It stands for shielded metal arc welding. It is a specific type of fusion welding process that uses an electrode with flux coating to create a welding arc between the electrode tip and the metal workpiece you use for your job.
We go into more detail about how this works below, but for now, this is a basic introduction.
So why is SMAW important? It’s one of the original forms of metal arc welding, the foundation of most modern welding practices. This welding technique is simple, affordable, and produces quality products.
Let’s look at a brief history of the arc of SMAW. It was invented in Russia in 1888 by a man named Gavrilovich Slavyanov. Initially, SMAW involved just a simple metal rod without any flux coating. As a result, it didn’t have a protective shielding gas.
Later, in the early 1900s, the flux-coated electrode was invented in Sweden alongside the Kjellberg process. The quasi-arc welding method appeared shortly after that in the UK.
How SMAW Works
Let’s now examine the processes and mechanics behind SMAW.
The flux coating of the electrodes in SMAW is one of the most essential components of this process, and there are three types of flux-coated electrodes: cellulosic, rutile, and basic.
The flux coating is so important because it protects the liquid (molten) metal from the welding process from atmospheric interference and oxidation. The flux coating also serves as alternative shielding to a shielding gas, as used in GMAW (gas metal arc welding).
So what’s the overall welding process like? Well, the flux coating gets deposited into the weld during the welding process, metamorphosing into slag. Slag isn’t a good thing, inherently, though it still serves a protective purpose. You must clear it from the worksite before making another weld pass; otherwise, the weld could be defective.
SMAW can use AC and DC power sources, so that’s your starting point, energy-wise. Once plugged in and powered on, the electrode produces a current, measured in voltage and amperes. This electric power then gets converted to heat over an energy arc, essentially the distance between the electrode tip and the workpiece.
This heat is exceptionally intense. Because of the power of the heat the energy arc generates, it melts metal on the spot, basically within fractions of a second. As welders, we must maintain that arc by keeping still and not closing in any of the space between the tip of the electrode and the molten metal part of the workpiece.
Benefits and Drawbacks
So what are the typical pros and cons of this welding method?
Equipment is cheaper, particularly compared to GTAW, FCAW, and GMAW (which, together with SMAW, are different complex welding processes).
Has a low deposition rate.
There is less equipment needed. For instance, you don’t need a bottle, gas source, flow meter, or wire feeder.
Equipment could cost more, given that filler metal per weld does have a low deposition rate.
SMAW is conducive to all sorts of environments, particularly smaller, more condensed spaces, the outdoors, in the light-medium wind, and all welding positions.
Requires professional-level hand-eye coordination and dexterity.
SMAW is highly portable, meaning you can easily move your worksite from one place to another.
You have to remove slag, unlike in GTAW/GMAW.
Doesn’t require a shielding gas.
Lower production factor.
- Don’t touch electrical parts when they’re on.
- Wear insulating, heat- and fire-resistant/retardant gloves and other forms of body protection, including clothes.
- Use dry insulation.
- Install the equipment precisely according to the specifications in the owner’s manual.
- Never weld metal without adequate ventilation.
- Take proper precautions to prevent fires and explosions.
- Wear eye protection at all times.
- Only use a fire-safe weld area.
- Do not weld metal on drums, tanks, barrels, or other containers, no matter what they’re made of.
- Inscribe the word “hot” into the metal with soapstone.
- Keep a well-stocked first aid kit at the ready.
Applications of SMAW
SMAW is a very versatile process and can be used for many different tasks, most often for heavy-duty work with tough metals like iron, steel, cast iron, and carbon steel. Conversely, its versatility lends itself to low- and high-alloy steels.
The uses and applications of SMAW include:
- Farm equipment manufacturing
- Welding underwater
Frequently Asked Questions
As we conclude this article, it’s important to recap some of what you’ve learned, so here’s a reminder set of questions and answers for some of the essential content we’ve covered.
What is the key differentiator that demarcates SMAW from other types of arc welding?
It’s all in the “S”: shielded metal. What this means is that every welding electrode used in shielded metal arc welding has a flux coating.
What are the five main applications and uses of SMAW?
They are construction, pipelines, building ships, manufacturing farm equipment, and welding underwater.
What’s one of the most important benefits of using SMAW?
It doesn’t require a shielding gas.
Who invented SMAW, and in what country?
Gavrilovich Slavyanov invented SMAW in Russia (in 1888).