Silicon Carbide Grades
FerrumX supplies silicon carbide in different quality grades and size ranges — standard splits, blends, fines, and customer-specific specifications.
Silicon carbide is classified by purity and by the process that forms it. Understanding the grade system helps match the right SiC to the application — from refractory and metallurgy to precision ceramics and abrasives.
What it is
What Silicon Carbide Grades Are & How They Form
Silicon carbide (SiC) is produced by high-temperature smelting of silica and carbon, then crushed and graded. It is split into quality grades by chemical purity and into sizes by application — from coarse lumps to micron powders.
Two formation routes define the family: metallurgical (black) silicon carbide, made from silica sand and petroleum coke, and green silicon carbide, made with salt additions for higher purity. Within each, the SiC percentage sets the grade.
Formation
Formation of Silicon Carbide Grades
Metallurgical (Black) Silicon Carbide
Produced from silica sand and petroleum coke in a resistance furnace. The typical black SiC grade spans roughly 90% to 98.5% SiC, used across refractories, metallurgy, and abrasives.
Green Silicon Carbide
Made with salt additions for higher purity. Used where low impurity and controlled particle shape matter — precision ceramics, slicing, and fine polishing.
Datasheet
Silicon Carbide Grades Datasheet
| Grade | SiC (%) | F.C (%) | Fe₂O₃ (%) | H₂O (%) |
|---|---|---|---|---|
| Grade I | ≥ 98.50 | ≤ 0.25 | ≤ 0.30 | ≤ 0.30 |
| Grade II | ≥ 88.50 | ≤ 2.80 | ≤ 3.00 | ≤ 0.50 |
| Grade III | ≥ 70.50 | ≤ 8.00 | ≤ 3.50 | ≤ 1.00 |
Properties
Silicon Carbide Properties
| Property | Value |
|---|---|
| Density | 3.21 g/cm³ |
| Vickers Hardness | 29 GPa |
| Coefficient of Thermal Expansion | 5 × 10⁻⁶ /K |
| Thermal Conductivity | 50 – 100 W/m·K |
| Temperature Resistance (in air) | 1500 °C |
| Temperature Resistance (inert atmosphere) | 2400 °C |
| Specific Heat | 750 J/kg·K |
FAQ
Silicon Carbide Grades — FAQ
By chemical purity (SiC percentage) into Grade I (≥98.5%), II (≥88.5%), and III (≥70.5%), and by formation route — black (metallurgical) vs green.
Black SiC is made from sand and coke for general use; green SiC adds salt for higher purity, used in precision ceramics and fine polishing.
Metallurgical black SiC in the 88–98% range is the standard for castables, taphole clay, and runners.
From 10–50 mm lump through coarse/medium/fine grains to micron powders (down to ~1 μm) and FEPA abrasive grades.
Yes — standard splits, blends, fines, and customer-specific PSD, binder, and packaging are available.
Density ~3.21 g/cm³, Vickers hardness ~29 GPa, thermal conductivity 50–100 W/m·K, and air-oxidation resistance to about 1500 °C.
