Dielectric Strength of Materials
Dielectric strength is one of the most important electrical properties of materials. The dielectric strength of a material is the maximum voltage required to produce electrical breakdown in that material. Dielectric strength is most commonly measured for insulators, as indicated by its’ name (dielectric is a synonym for insulator). The following is a table showing the dielectric strength of many common materials.
| Material | Dielectric Strength (MV/m) |
| Air | 3 |
| Alumina | 13.4 |
| Bakelite | 25 |
| Barium titanate | 7.5 |
| Benzene | 163 |
| Borosilicate glass | 20-40 |
| Diamond | 2,000 |
| Distilled water | 65-70 |
| Freon | ~8 |
| Fused silica | 470-670 |
| Gallium arsenide | ~40 |
| Germanium | ~10 |
| Glass (plate) | 30 |
| Helium | 0.15 (relative to nitrogen) |
| High vacuum (compare with perfect vacuum) | 30 |
| HDPE (high density polyethylene) | 20 |
| Mica | 118 |
| Mineral oil | 10-15 |
| Neoprene | 15.7-26.7 |
| Nylon | 14 |
| Paper | 15 |
| Paraffin | ~30 |
| PEEK (polyether ether ketone) | 23 |
| Polyethylene | 19-160 |
| Polystyrene | 19.7 |
| Porcelain | 12 |
| PTFE (Teflon) | 19.7 – 173 |
| PZT (lead circonate titanate) | 10-25 |
| Rubber | 12 |
| Silicon | ~30 |
| Sulfur hexafluoride | 8.5-9.8 |
| Transformer oil | 24 |
| Vacuum (perfect) | 1012 |
| Waxed paper | 40-60 |
| Window glass | 9.8-13.8 |
| Wood (Douglas fir) | ~10 |