Metal Finishing Expert Advice

The difference between Silicone Carbide and Aluminium Oxide

At Moleroda we have hundreds of nuggets of advice on metal finishing. One of the questions we are regularly asked is what wet and dry paper to use and what does each material type mean.

Here we detail the difference between silicone carbide and aluminium oxide. We hope this will ensure you are buying the right economy roll or wet and dry or even self adhesive discs for you!

What is Silicon carbide and Aluminium oxide? 

Silicon carbide (SiC) and aluminum oxide (Al2O3) are two common types of abrasive materials used in wet and dry sandpapers.

The differences between the two:

Hardness

Silicon carbide is harder than aluminum oxide. It has a Mohs hardness of 9-9.5, making it one of the hardest abrasive materials available. Aluminum oxide, on the other hand, has a slightly lower hardness with a Mohs rating of 9. However, both materials are significantly harder than most metals and are effective for grinding and sanding applications.

Sharpness

Silicon carbide particles tend to be sharper and more aggressive compared to aluminum oxide particles. This sharpness allows silicon carbide to cut through harder materials with greater ease. It is particularly effective for sanding materials like stone, glass, ceramics, and hardened steel.

Material compatibility

Silicon carbide is suitable for both wet and dry sanding applications. It excels in wet sanding as the material resists clogging and retains its cutting ability. Aluminum oxide is also compatible with wet and dry sanding but may be more prone to clogging when used in wet conditions.

Finishing capabilities

While both abrasives can achieve smooth finishes, aluminum oxide is often favored for fine finishing applications. It is capable of producing a more refined surface compared to silicon carbide. Aluminum oxide is commonly used for final polishing or creating a mirror-like finish on metals.

Applications

Silicon carbide is often preferred for harder materials, such as stone, ceramics, and non-ferrous metals. It is commonly used in applications like grinding, shaping, and polishing.

Aluminum oxide is versatile and widely used in various industries, including woodworking, metalworking, and automotive refinishing. It is suitable for sanding and finishing both hard and soft materials, such as wood, metals, and composites.

Also remember..

When choosing between silicon carbide and aluminum oxide wet and dry sandpapers, consider the material you are working with, the desired finish, and the specific application requirements.

It’s also worth noting that sandpapers often come with different grit sizes, allowing for different levels of abrasiveness and surface finish.

More Information 

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