What is Resistance Welding?

When one thinks about welding, the idea that probably comes to mind is that of using heat to melt two pieces of metal in order to join them and create a single part. While that is a correct description of a welding process, it is not the only one. Another type of welding is resistance welding.

So what is resistance welding? How does it differ from the process most people probably think of when they hear the term welding?

The resistance welding process, also sometimes called electric resistance welding, involves the application of pressure and the conduction of a strong electrical current to heat and melt metals so that they can be joined together. Because no other materials are required to create the bond, the process is highly cost-effective.

One can use a resistance welding machine for a number of different applications in the automotive, aerospace, and other industries. A reason for its versatility is that there are several types of resistance welding, with the major difference between them being the type and shape of the weld electrodes used. These resistance welding electrodes are used to apply pressure and conduct the electrical currents. Typically, they’re made from copper due to copper’s excellent conductive qualities, and they’re cooled by water.

Types of Resistance Welding

Each type of resistance welding has its own specific welding application. In effect, each type is the optimal one for a particular situation.

• Resistance Spot Welding: One of the oldest and simplest forms of resistance welding, resistance spot welding is popular with the automotive industry, which uses it to join steel, and the aerospace industry, which uses it for aluminum alloys in airframe components.
• Resistance Seam Welding: A variation of spot welding, resistance seam welding produces a series of overlapping nuggets, areas on the base material formed where two metals have been joined. A common application is the production of leak-tight containers, such as fuel tanks, made from thin sheets.
• Resistance Projection Welding: This process concentrates force and electricity on raised surface projections. It’s good for thicker materials and is used a lot by the automotive, construction, and electrical industries.
• Resistance Butt Welding: Whereas some of the other resistance welding processes focus on small spots, this process allows for operation across the entirety of an object. This is often the preferred process for creating rods and wires with smaller diameters.
• Flash Butt Welding: This is similar to resistance butt welding, but the energy transfer comes from resistance heat emanating from the parts themselves. It’s one of the fastest types of resistance welding.

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Advantages and Disadvantages of Resistance Welding

There are always pros and cons to any process. The advantages of resistance welding are that it can join both similar and dissimilar metals; it’s highly automated, efficient, and cost-effective; it produces little waste and pollution; and there’s no need for filler metals or extraneous materials.

Drawbacks include complex, high-cost machinery; high use of electrical power; and limitations in thickness of work pieces.

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Find a Resistance Welder Near You

If you need resistance welding services, Sustainment can help you find a local resistance welding company that can meet your needs. With our powerful, user-friendly search feature, you can find a vetted, reputable resistance welder near you, which will save you time and let you focus on other aspects of your business.