Choosing the Best Abrasive Powder for the Job

Micro-abrasive blasting offers precision and control for applications from do-it-yourself projects to highly complex machining for the aerospace industry. Whether you need to etch intricate designs on glass or remove graphite residue from a machined part, choosing the correct abrasive powder is critical to your success.

Terminology

Understanding a few key terms will help you choose the right abrasive powder.

Depth Profile – When you use micro-abrasive blasting, the powder particles form small peaks and valleys as they strike the surface. The depth profile, or anchor pattern, describes the size of these indentations by measuring the distance from the top of the peak to the bottom of the valley.

A deeper profile allows for stronger adhesion when applying coating. At the same time, if the peaks extend beyond the coating, rust can occur. Knowing the final coating thickness will help you determine the desired depth profile.

Microns – One micron equals one, one-millionth of a meter. Depth profile and particle size are typically measured in terms of microns.

Mesh Size – Mesh size is another way to describe particle size. Particles are passed through a steel wire weave (like a strainer). For instance, a mesh size of 325 (equal to 44 microns) means that 95 percent of the particles pass through a mesh screen that includes 325 openings in one linear inch of screen.

4 Abrasive Properties to Consider

To obtain the desired finish and profile depth for the surface you are preparing, you need to consider the four main properties of abrasive powders. These include size, shape, hardness and density.

Size – Bigger particles result in deeper indentations, which can help coatings to adhere. On the other hand, smaller particles provide better surface coverage and clean surfaces more rapidly.

Shape – Particle shape is described in terms of angularity. For instance, an angular-shaped abrasive media is useful for cutting through soft surface contaminates like rust. Round-shaped particles, like glass beads, make less of an indentation and are good for peening or creating a softer finish.

Hardness – Harder abrasive powders result in a deeper depth profile and generally remove surface contaminants more quickly. An abrasive like silicon carbide is therefore very effective for cutting and deburring.

Density – Denser particles strike the surface with more force, making a deeper indentation in a smaller surface area.

Abrasive Powder Types

Airbrasive offers a number of high quality abrasive powders for a variety of micro-abrasive blasting applications. Whether you choose the 27 Micron Aluminum Oxide Blend for etching or the 50 Micron Silicon Carbide Mixture for deburring, you will find a product with proven performance and reliability.

All our abrasive powders are double-screened, sieve-tested and vacuum-packed. They have been tested for purity and come in a selection of materials and particle sizes. We can even customize a formulation for your specific needs.