How Do I Select the Right Grade of Abrasive?

Posted in Abrasive Media

The wrong grade abrasive can reduce productivity and cause waste

When preparing your blasting project it is vital to use an abrasive grade (size) that will give you the best performance. If the wrong size abrasive is used productivity can be reduced and abrasive consumption can be excessive. There are two facts to take into consideration when choosing abrasive.


Abrasive blasting works by using the impact of each grain of sand hitting the surface to 'chip off' the unwanted material. Therefore the more impacts you can get the quicker the job gets done. To increase the number of impacts you need to increase the number of grains of abrasive hitting the surface. These increases are achieved by reducing grain size.

More grains per volume of abrasive = more impacts = more production.

Small particles per square inch Large particle size per square inch


The relationship between the abrasive particle size and contaminant thickness requiring removal needs to be considered to ensure maximum productivity. This is because fast contaminant removal is dependent on the abrasive particle being of sufficient size to cut through the contaminant and impact directly on the substrate.

The correct grade of abrasive is the finest one that closest matches the thickness of the surface element being removed.

Coating thickness comparison chart

Coating Thickness Milscale to 10mil 10 - 20 mil 15 - 30 mil 30+ mil 50+ mil    
Abrasive GMA NewSteel Garnet GMA SpeedBlast Garnet GMA Premium Blast Garnet GMA UltraBast Garnet 40,000psi WaterJet 20/40 Slag Fine Slag
Approx profile 1.5 to 2.5 mil 2.5 to 3.5 mil 2.5 to 3.5 mil 3 to 4 mil   2 to 4 mil 1 to 2.5 mil

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