Aluminum Oxide Vs Silicon Carbide

Aluminum oxide is the ideal material to use when it comes to sanding metal and wood with higher tensile strengths, as well as grinding some tough steels that contain hard carbides such as chromium, vanadium or tungsten.

Silicon carbide boasts razor-sharp grains that cut glass, plastic and metal with minimal pressure, yet wears down faster than aluminum oxide. Unfortunately, its sharp edge also wears down quickly.


Aluminum oxide is one of the toughest, longest-wearing abrasives on the market, boasting a Mohs scale hardness of 9 and non-contamination for use on glass, plastic and rubber surfaces. Available from 16 to 600 grit sizes for optimal use on these substrates, aluminum oxide offers longer wear life than silicon carbide which has harder, sharper grain structure that wears faster.

Aluminum oxide abrasive grain works well on metal, wood, and painted surfaces; from coarse through microgrit products. Available from coarse through micro grit sizes and with various backings affixed. Brown aluminum oxide grain is widely used due to its semi-friable characteristics that work on both soft metals such as brass and wood surfaces; more affordable than silicon carbide alternatives.

White and pink grains of aluminum oxide abrasives typically last shorter than their brown counterparts; however, they work much better for processes involving lacquers or bare metals because they produce less heat, enabling more effective cutting action on soft materials while decreasing risk of heat damage to surfaces being worked upon.

Aluminum oxide abrasives are generally the better choice when working on stainless steel surfaces, due to their resistance against gumming-up and rapid material removal rate. Silicon Carbide may require more aggressive grinding processes that may overheat and damage substrate being worked upon, making its use more challenging.


Aluminum oxide abrasive is more reliable and long-wearing than silicon carbide, maintaining its cutting edges for extended periods. This helps minimize rework when sanding tough materials like metal and stone. Silicon carbide on the other hand has more brittle grains that break down more quickly when coming into contact with difficult substances, resulting in less precise sanding and slower material removal.

Silicon carbide’s durability can also be determined by its chemical stability and electrical characteristics, unlike aluminum oxide which conducts electricity very effectively and is resistant to corrosion. Due to these limitations, silicon carbide may prove challenging when working on certain materials using power sanding machines.

Aluminium oxide stands out for its superior finish quality and longevity, as well as its outstanding heat resistance, making it an excellent abrasive choice for numerous woodworking applications, such as rough sanding or in between coats of finish sanding.

Silicon carbide abrasive sheets, on the other hand, are better suited to finishing tasks than rough sanding due to its sharper, more aggressive abrasive properties and ability to cut through materials with high tensile strength. Silicon carbide can also be used in wet sanding applications such as polishing stone and marble surfaces and removing rust from metal components or refinishing wood flooring in coarser grits.


Aluminum oxide is known for being durable and its ability to resist heat degradation is due to its excellent thermal conductivity and chemical stability, making it ideal for blasting abrasive materials such as granite. Due to its durability, several blast cycles may pass before needing replacement which helps save both costs and downtime.

Silicon carbide on the other hand is more brittle and wears down faster over time, leading to less consistent performance than aluminum oxide abrasives. While its razor-sharp grains may work to cut glass, plastic, medium density fiberboard with light pressure applications, they struggle with harder metals or wood that require heavier pressure for sanding.

Aluminium oxide and silicon carbide abrasives both work well on steel, with aluminum oxide being better at managing heat generated during polishing processes – this makes it more suitable for working on harder materials such as stainless steel or titanium.

Aluminum oxide is more effective at combatting rust than silicon carbide because silicon carbide tends to leave behind residue of iron and chromium that makes removing rust difficult; aluminum oxide on the other hand is non-contaminating and can easily remove rust without harming underlying materials.


Silicon carbide and aluminum oxide abrasive materials differ significantly when it comes to task use; each one being better suited for certain tasks than the other. Silicon carbide offers hard and long-wearing performance while aluminum oxide offers less complex solutions suited for more delicate or low tensile strength applications.

Aluminum oxide is often chosen for ceramic work due to its effectiveness at surface finishing and polishing, creating an even surface with its round particles, which enhances aesthetic appeal. Furthermore, this gentle material also works great as an abrasive for glass and metal pieces as it won’t damage them over time.

Silicon carbide, on the other hand, is an even sharper and harder material than aluminum oxide. Its razor-sharp grains cut glass, plastic and medium-density fiberboard effortlessly with light pressure but cannot cut hardwoods or metals as easily. Because of its narrow shape and brittle nature, silicon carbide also abrasives often require replacement after shorter blast cycles or when sanding more challenging materials.

Silicon carbide and aluminum oxide both work for stainless steel workpieces, though silicon carbide will offer an edge against more wear-resistant alloys containing chromium, vanadium or tungsten carbides. While working with these metals it will likely ‘gum up’ more quickly than its Al2O3 counterpart;

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