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Glass silicone is a good choice for fabricated parts that need to have excellent insulative properties

Glass / Silicone (G-7)

  • Outstanding electrical properties
  • Excellent heat and arc resistance
  • Self-extinguishing
  • UL 94V-O Flame class rating


This glass-silicone laminate has excellent dielectric loss properties under dry conditions and good electrical properties under humid conditions. It also has excellent heat and arc resistance and is self-extinguishing. It is often used for electrical grade insulation as well as heating and appliance insulation.

While silicones do not retain their strength as well as epoxies and phenolics over time under lower temperatures, they are stronger over time under high heat conditions (over 400 degrees F).


  • Electrical grade insulation
  • Heating and appliance insulation
  • Shoulder bushings
  • Lock bolt washers
  • Arm insulating plates
  • Bus tube standoffs


Our application engineers can help. With decades of experience in plastic material selection, we'll help you choose the optimal plastic for your application and budget.

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General Material Properties

Property   Typical value units
Specific Gravity/Density   1.75 g/cm3
Water Absorption -.125"   < .35 %
Temperature Index   220 \ 428 °C \ °F
Hardness (Rockwell)   100 M scale
Bond Strength   > 700 \ 320 lbs \ kgs
Flexural Strength-LW-A-.125"   > 25,000 \ 173 PSI \ MPa
Flexural Strength-CW-A-.125"   > 22,000 \ 152 PSI \ MPa
Izod Impact Strength-LW   > 10 ft-lbs/in
Izod Impact Strength-CW   > 8 ft-lbs/in
Compressive Strength-Flatwise   > 47,000 \ 324 PSI \ MPa
Dielectric Breakdown-A   > 50 kV
Dielectric Breakdown-D48/50   > 30kV
Permittivity-A   < 4.0  
Arc Resistance-A   180 SEC
Dissipation Factor-A   0.003  
Dissipation Factor-D24/23   0.020 

The information on this page is intended as general guidance only and is only accurate at the time of posting (see date below). Specific material properties vary by manufacturer. Please contact a Dielectric application engineer for help in choosing the optimal material for your application and budget.

Posting Date: October 12, 2012