Aluminum Oxide Sandpaper Vs Silicon Carbide Sandpaper

Abrasives are available in a wide variety of materials and grits. Depending on your application, one of the other options may be more cost effective, longer lasting or simply better at the job than aluminum oxide. For example, working a piece of wood from coarse through a fine finish could benefit from using a combination of grains to navigate the surface.

Aluminum Oxide

Aluminum oxide, also known as brown aluminum oxide or semi-friable, is the most versatile of the synthetic abrasive grain types and comes in coarse through micro grit products affixed to various backing materials including paper, cloth and polyester. It is particularly good for softer metals, fiberglass, drywall and painted/primed surfaces. In grits of 80 through 180, it works well with moderate pressure/tension. In the finer grits, aluminum oxide tends to clog more quickly than other materials, so it is typically paired with silicon carbide in those applications.

Silicon Carbide is a harder and sharper abrasive grain than aluminum oxide, and it can often be used to replace aluminum oxide in certain applications where there is a need to cut through hard surfaces like metals and wood. However, its razor-sharp grains can make it difficult to work through tougher materials with light pressure. It also is not as durable as aluminum oxide, as its brittle and narrow shape tends to wear down at an increased rate. For these reasons, it is common to use silicon carbide sandpaper when roughing a material and then switch to aluminum oxide for finishing.