Maximizing Efficiency: Tips for Selecting and Using Welding Abrasives

Abrasives are essential at all stages of the welding process. They can be used to prepare, repair, and smooth out finished welds.

Selecting the right abrasive can help professionals create strong and durable products while enhancing productivity. But the process of picking one can be complicated. Let’s take a closer look at some of the considerations in choosing the proper abrasive.

Understanding Abrasive Tools  

Several types of abrasive tools are used in welding—from brushes to discs and belts. The tool you use depends on the specific project.

For an idea of what to look for, let’s explore the differences between various discs. 

Grinding and flap discs are used to smoothen surfaces, remove weld seams, and grind edges. But a grinding disc is more commonly used when a lot of material needs to be removed quickly and the finish is not that important. Meanwhile, a flap disc is a better choice for finishing as it helps polish a weld without gouging the surface.

A cutoff wheel, such as Flexovit’s Razorblade series, is also used to cut through the metal for production and maintenance applications.

Selecting Abrasive Materials

The abrasive grain can be made up of many materials, but the ones usually used in welding include aluminum oxide, silicon carbide, or zirconia alumina (a mixture of aluminum oxide and zirconium oxide).

Choosing the right grain is vital for a welder.

Aluminum oxide performs well in a wide range of applications. It’s best suited for working with ferrous metals. A Flexovit aluminum oxide wheel, for example, can be used for surface preparation jobs that require moderate to heavy stock removal.

Silicon carbide, on the other hand, works best on non-ferrous metals like aluminum.

Zirconia is known for its toughness and is suited for heavy-duty grinding applications. The PFERD zirconia alumina flap disc is known for being extremely long-lasting—saving costs while improving efficiency.

Determining Grit Size

Grit size—or the size of the abrasive particles used—is another important metric. The choice of grit depends on the welding process and the material being worked on. 

Coarser grits, which have a lower number, may remove material faster but can create scratches on the surface. Finer grits, which are represented by a higher number, result in a more time-consuming removal process but are better suited for finishing.

The goal is to strike the right balance—finding a grit size that removes a sufficient amount of material quickly without weakening the weld.

A good place to start is to choose a grit size between 40 and 60, then make adjustments according to the results. If you find that you need a finer grit, look for abrasive wheels, such as the Polifan Z SG Power flap disc, which have a grit size of 80.

Assessing Max RPM Speed

When selecting a cutting, grinding wheel, or flap disc, the manufacturer’s recommended maximum RPM must be taken into account.

Exceeding the maximum RPM can pose a potential safety hazard or damage the metal. Operating a disc at a lower RPM than its maximum results in reduced performance and efficiency.

For an idea of the RPM range, consider this—the PFERD 7” x 1/4 Grinding Wheel has a maximum RPM of 8500 while the PFERD 4-1/2” x 1/4 Grinding Wheel has a maximum RPM of 13300. Both will not work on the same tool. 

Forge Forward With nexAir

At the end of the day, selecting and using the right abrasive depends on the complexity of the project, the type of metal used, and the budget.

At nexAir, one of the leading suppliers of welding equipment across the Southeast, we believe that picking an abrasive with the right KnowHow is crucial for those looking to Forge Forward with improved efficiency and lower costs.

Check out our comprehensive list of abrasives to find one that’s right for you.