Welding Techniques Used for Sheet Metal

Steel became a game-changer when it was first introduced as a construction material in the late 1880s. It is formable, durable, and serves for decades without specific maintenance.

But the question is, how to weld steel parts together so that they hold firmly? Engineers and welders use several techniques for different types of steel products. This time, you will learn about three welding techniques used to join metal sheets.

Sheet Metal Welding Process Types

All welding techniques use the same principle – they join metal using heat. The two pieces of metal melt under high temperatures and solidify when the heat source is removed.

The difference between popular welding technologies comes from the heat source and the material used to join the two pieces of metal.

Shielded Metal Arc Welding (SMAW)

Shielded metal arc welding is the oldest way to join two metal sheets. It is also a manual, labor-intensive process that requires a welder to show professional skills. Many welders informally call it “stick welding.”

The system consists of a power generator, a welding cable, and a hand manipulation with a detachable electrode (a stick).

The power generator transmits current to the electrode and heats it. At over 7,000° F, the electrode melts and forms the weld that attaches two metal sheets.

Engineers call it “shield welding” because once the electrode melts, it emits a stream of protective gas that isolates the weld area from oxygen.

Pros of stick welding:

  • It’s portable. A welder can carry a power generator wherever they want.
  • It’s convenient. A welder can lay a weld in different positions at different angles.
  • It’s cheap as it doesn’t require sophisticated equipment or intensive pre-welding steel cleaning preparations.

Cons of stick welding:

  • It leaves slag at a welding point. You have to remove it afterward.
  • Inexperienced welders can burn electrodes through thin metal sheets.
  • Welders have to replace electrodes often while working on large projects.

Metal Inert Gas Welding (MIG)

Metal inert gas welding uses the same concept as stick welding, except that it involves electrode wire.

Additionally, it requires extra shielding gas as the electrode wire doesn’t produce it, unlike the stick.

Pros of MIG welding:

  • It’s semi-automatic as the welder controls only the welding position, distance, and speed. The power unit controls the wire feeding rate automatically.
  • It welds thin metal sheets much faster and easier.

Cons of MIG welding:

  • It requires initial metal cleaning because it doesn’t weld dirty steel well.
  • It leaves corrosive deposits on the weldable area.

Automated Laser Welding

Laser welding uses precision laser equipment to join metals through heat. A laser machine focuses a laser on the welding point. It heats the joinable area – the steel melts and creates a uniform joint when it cools down. 

Pros of laser welding:

  • It produces clean and narrow welds, minimizing the melting area and steel distortion caused by heat.
  • It’s precise and easy to use. Just input steel stock into the laser welding machine and let it do its job.
  • It makes strong welds.

So the best welder for sheet metal might appear to be a laser one. However, laser welding involves some drawbacks:

  • It requires substantial investment as such welding equipment costs $20,000 per unit on average.
  • It might create porous welds due to the rapid cooling of metal.
  • You must attach the weldable joints accurately so that they have a minimal gap in between.

How Does Metal Quality Affect Welding?

Buying the best welder for thin metal is not enough to deliver consistent results. You have to choose metal carefully since a wrong steel grade can turn welding into a nightmare. Make sure you buy steel sheets that:

  • Consist of weldable steel grades.
  • Have minimal rust and other surface imperfections.
  • Resist corrosion.

You can order a high-quality steel sheet by Metinvest to ensure that you use the most suitable metal for your welding works.

Final Thoughts

Today’s metal industry uses different types of welding for metal sheets. MIG, stick, and laser welding have become some of the most popular ones. These welding approaches use the same concept – they join metal through immense heat.

Each of these technologies has distinctive advantages and disadvantages, so you can stick to one that suits your budget and needs the most.

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