Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

This is an AMP page - Open full page! for all features.

Dielectric Strength of Insulating Materials

Sponsored Links

The dielectric strength of a material is the ability to the material to act as an insulator.

The dielectric strength of a material is the voltage that a material of a given thickness will resist. With higher voltage than the dielectric strength a spark will pass through the material.

Dielectric Strength of Insulating Materials
MaterialDielectric Strength
(106 V/m)(V/mil)
Mica (muscovite) 39.4 1000
Glass 35.5 900
Mica (phlogopite) 31.5 800
Porcelain (electrical) 31.5 800
Steatite 29.6 750
Rubber, hard 27.6 700
Rubber, silicone 23.6 600
Polystyrene 23.6 600
Pyroxylin 23.6 600
Rubber, buna 20.3 515
PTFE 19.7 500
Vinylidene chloride 19.7 500
Fish paper 19.7 500
Methyl methacrylate 18.9 480
Cellulose acetate 15.8 400
Casein plastic 15.8 400
Shellac 15.8 400
Varnished cambric 15.8 400
Alumina 13.4

The dielectric strength is usually given in volts per mil where 1 mil equals 0.001 in, or volts per meter.

  • 1 V/m = 2.54 10-5 V/mil
  • 1 V/mil = 3.94 104 V/m
Sponsored Links

Related Topics


Electrical engineering with units, amps and electrical wiring. Wire gauges, electrical formulas, motors and more.

Related Documents

Electrical Conductivity - Elements and other Materials

Electric conductance is the ability of a element to conduct an electric current.

Liquids - Dielectric Constants

Dielectric constants or permittivities of some fluids or liquids.

NEMA Insulation Classes

Electrical insulation systems rated by standard NEMA classifications to maximize allowable operating temperatures.

Relative Permittivity - the Dielectric Constant

Common materials and their relative permittivity.

Sponsored Links

Search Engineering ToolBox

  • the most efficient way to navigate the Engineering ToolBox!

SketchUp Extension - Online 3D modeling!

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with the amazing, fun and free SketchUp Make and SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp from the Sketchup Extension Warehouse!


We don't collect information from our users. Only emails and answers are saved in our archive. Cookies are only used in the browser to improve user experience.

Some of our calculators and applications let you save application data to your local computer. These applications will - due to browser restrictions - send data between your browser and our server. We don't save this data.

Google use cookies for serving our ads and handling visitor statistics. Please read Google Privacy & Terms for more information about how you can control adserving and the information collected.

AddThis use cookies for handling links to social media. Please read AddThis Privacy for more information.