---
title: "Silicon carbide — density, melting point and properties"
description: "Silicon carbide has a density of 3,210 kg/m³. Melting point, strength, conductivity, what it is used for, and whether it floats, rusts or is magnetic."
url: https://atoneplace.net/material/silicon-carbide/
site: "At One Place"
---

# Silicon carbide

**Density of silicon carbide: 3,210 kg/m³**

3.21 g/cm³ · 200.4 lb/ft³

It does not melt: at atmospheric pressure it sublimes and decomposes above about 2700 °C, which is why no melting figure is given here. Harder than alumina at Mohs 9.5 and with four times the thermal conductivity, so it survives thermal shock that would shatter a comparable alumina part, and it is the standard kiln shelf material for that reason. Its wide bandgap has made it the material of choice for electric vehicle traction inverters, where SiC transistors switch faster and run hotter than silicon.

## Properties

- **Density:** 3,210 kg/m³ — 3.21 g/cm³
- **Tensile strength:** 250–400 MPa
- **Young's modulus:** 410 GPa
- **Thermal conductivity:** 120 W/(m·K)
- **Hardness:** 9.5 Mohs
- **Thermal expansion:** 4 µm/(m·K)
- **Floats in water:** No
- **Magnetic:** No

## What it is used for

- Abrasive paper, wheels and lapping compound
- Kiln shelves and furnace elements
- Mechanical seal faces and pump parts
- High-voltage power semiconductors

## How it compares

*Water is 1,000 kg/m³. Anything with a shorter bar than water floats in it.*

- air: 1.2 kg/m³
- expanded polystyrene foam: 20 kg/m³
- rigid polyurethane foam: 40 kg/m³
- Water — the float line: 1,000 kg/m³
- silicon carbide: 3,210 kg/m³
- tungsten: 19,250 kg/m³
- gold: 19,300 kg/m³
- platinum: 21,450 kg/m³

*Water is 1,000 kg/m³. Anything below that floats.*

| Material | Density | Relative to water |
| --- | --- | --- |
| rigid polyurethane foam | 40 kg/m³ | 0.04× |
| expanded polystyrene foam | 20 kg/m³ | 0.02× |
| air | 1.2 kg/m³ | 0.00× |
| silicon carbide ← | 3,210 kg/m³ | 3.21× |
| platinum | 21,450 kg/m³ | 21.45× |
| gold | 19,300 kg/m³ | 19.30× |
| tungsten | 19,250 kg/m³ | 19.25× |

## Does it rust?

Silicon carbide contains no iron, so it cannot rust. Whether it degrades depends on the material, not on oxidation.

## Is it magnetic?

Silicon carbide is not a metal and has no ferromagnetic response.

## Common questions

### What is the density of silicon carbide?

3,210 kg/m³, or 3.21 g/cm³.

### Does silicon carbide float?

No. At 3,210 kg/m³ it is denser than water.

### Is silicon carbide magnetic?

Silicon carbide is not a metal and has no ferromagnetic response.

## Related pages

- [Does silicon carbide float?](https://atoneplace.net/does-it-float/silicon-carbide/)
- [Concrete](https://atoneplace.net/material/concrete/)
- [Brick](https://atoneplace.net/material/brick/)
- [Gypsum board (drywall)](https://atoneplace.net/material/gypsum-board/)
- [Tungsten carbide](https://atoneplace.net/material/tungsten-carbide/)
- [Reinforced concrete](https://atoneplace.net/material/reinforced-concrete/)
- [Graphite](https://atoneplace.net/material/graphite/)
- [Porcelain](https://atoneplace.net/material/porcelain/)
- [Plaster](https://atoneplace.net/material/plaster/)

## Sources

- Typical range compiled from manufacturer specifications — At One Place (/about/)