What Is Carborundum Used For?

Overview:
Carborundum, commonly known as silicon carbide (SiC), is one of the hardest synthetic materials used in modern industry. Due to its exceptional hardness, high thermal resistance, chemical stability, and sharp cutting edges, carborundum is widely used in grinding, polishing, sandblasting, refractory manufacturing, electronics, automotive production, aerospace engineering, and advanced semiconductor applications. This comprehensive guide explains what carborundum is used for, how its properties influence performance, and how different grades and grit sizes are selected for specific industrial applications.

Table of Contents

• 1. What Is Carborundum?
• 2. Key Properties of Carborundum
• 3. Carborundum in Abrasive Applications
• 4. Carborundum for Sandblasting and Surface Preparation
• 5. Carborundum in Refractory and High-Temperature Industries
• 6. Carborundum in Electronics and Semiconductor Manufacturing
• 7. Carborundum in Automotive and Aerospace Engineering
• 8. Carborundum in Construction and Stone Processing
• 9. Other Specialized Uses of Carborundum
• 10. Carborundum Grades and Grit Size Selection
• 11. Conclusion

1. What Is Carborundum?

Carborundum is the historical trade name for silicon carbide (SiC), a synthetic compound composed of silicon and carbon. It was first produced in the late 19th century using an electric resistance furnace process, where silica sand and carbon are heated to extremely high temperatures above 2000°C. The resulting crystalline material forms sharp, durable grains ideal for industrial use.

Silicon carbide is one of the hardest materials available, ranking approximately 9.2 to 9.5 on the Mohs hardness scale. It is second only to diamond and boron carbide among commonly used industrial materials. Because of this hardness and its excellent thermal and chemical stability, carborundum has become essential across multiple industries.

Carborundum is available in various forms, including:

• Black silicon carbide (general-purpose abrasive grade)
• Green silicon carbide (higher purity, sharper cutting ability)
• Refractory grade silicon carbide
• Metallurgical grade silicon carbide
• Micro powder for precision polishing

Each type serves different industrial purposes depending on purity, grain size, and application requirements.

2. Key Properties of Carborundum

The wide range of carborundum applications comes directly from its unique physical and chemical properties:

• Extreme hardness and sharp grain structure
• High thermal conductivity
• Low thermal expansion
• Excellent wear resistance
• High melting point (over 2700°C)
• Strong chemical stability
• Resistance to corrosion and oxidation

These characteristics make carborundum particularly suitable for abrasive cutting, grinding, surface preparation, and high-temperature structural applications.

3. Carborundum in Abrasive Applications

The most common use of carborundum is in abrasive manufacturing. Because of its hardness and sharp edges, it provides fast cutting action and long service life.

Grinding Wheels

Carborundum is widely used in bonded abrasive grinding wheels. It is especially effective for grinding non-ferrous metals such as aluminum, brass, copper, and also for cast iron and stainless steel. The sharp grains fracture during use, constantly exposing fresh cutting edges.

Coated Abrasives

Silicon carbide grains are used in sandpaper, abrasive belts, and discs. These are commonly applied in woodworking, automotive refinishing, and metal polishing.

Lapping and Precision Polishing

Fine and micro grit silicon carbide powders are used in precision lapping processes for achieving high surface smoothness on metals, ceramics, and optical components.

Typical abrasive grit ranges include:

• F24 to F60 for heavy stock removal
• F80 to F220 for intermediate grinding
• F240 to F600 for fine finishing
• F800 to F3000 for precision polishing

4. Carborundum for Sandblasting and Surface Preparation

Carborundum is frequently used as blasting media due to its aggressive cutting performance. It is ideal for:

• Rust removal
• Paint stripping
• Scale removal
• Surface texturing
• Pre-coating surface preparation

Compared to softer blasting media, silicon carbide provides faster cleaning speed and deeper surface profiles. It is commonly used in steel fabrication, bridge maintenance, shipbuilding, and heavy industrial maintenance.

5. Carborundum in Refractory and High-Temperature Industries

Because of its high melting point and thermal conductivity, carborundum plays an important role in refractory manufacturing. It improves strength, thermal shock resistance, and durability in extreme environments.

Common refractory applications include:

• Kiln furniture
• Furnace linings
• Crucibles
• Refractory bricks
• High-temperature ceramic components

Carborundum helps reduce energy loss while increasing furnace efficiency and service life.

6. Carborundum in Electronics and Semiconductor Manufacturing

High-purity green silicon carbide is used in advanced electronics and semiconductor industries. Silicon carbide wafers are increasingly important in:

• Electric vehicle power systems
• Solar inverters
• High-voltage switching devices
• Industrial power electronics

Compared to traditional silicon semiconductors, SiC-based devices offer higher efficiency, faster switching speeds, lower energy losses, and superior performance at high temperatures.

7. Carborundum in Automotive and Aerospace Engineering

In automotive manufacturing, carborundum is used for:

• Brake system finishing
• Engine component grinding
• Surface preparation before coating
• Precision machining of metal parts

In aerospace engineering, silicon carbide is used in advanced ceramic composites and high-temperature components due to its lightweight and heat-resistant properties.

8. Carborundum in Construction and Stone Processing

Construction and stone industries rely heavily on carborundum for:

• Concrete floor grinding
• Marble and granite polishing
• Terrazzo finishing
• Stone cutting

Its durability ensures consistent performance even when processing hard mineral materials.

9. Other Specialized Uses of Carborundum

Beyond mainstream industrial uses, carborundum is also used in:

• Anti-slip coatings for industrial floors
• Abrasive additives in paints and sealants
• Water filtration systems
• Armor and protective materials
• Heating elements

Its versatility makes it a valuable engineered material in both traditional manufacturing and emerging technologies.

10. Carborundum Grades and Grit Size Selection

Selecting the correct carborundum grade depends on:

• Application type
• Required surface finish
• Material hardness
• Operating temperature
• Desired removal rate

Coarse grit sizes are used for aggressive grinding, while fine and micro powders are selected for high-precision polishing. Higher purity grades are required for electronics and semiconductor applications.

11. Conclusion

Carborundum is used in a wide range of industries due to its exceptional hardness, durability, and thermal stability. From abrasive grinding wheels and sandblasting media to refractory components and semiconductor wafers, its applications continue to expand as industrial technology advances.

Understanding what carborundum is used for allows manufacturers, engineers, and buyers to select the appropriate grade and grit size for their specific needs. Whether the goal is aggressive material removal, high-temperature resistance, or precision surface finishing, carborundum remains one of the most reliable and versatile materials in modern industry.