Cast Epoxy Insulators

Choose Epoxy for Superior:

Cast Epoxy Insulator
  • Wear
  • Crack and Shatter Resistance
  • Electrical Insulating
  • Adhesion to Metal and Wood
  • Chemical Resistance
  • Impact strength
  • Design intricacy options
  • Value
  • Sealing


Cast Epoxy
  • Standoffs 5 to 20 Kv
  • Bushings: Wire and Studded
  • Low Voltage Bushing
  • Low Voltage Secondary
  • Insulating Sleeves, Bus Bar Supports, Tubes, Flanges, Spacers
  • Replacement Components, Part Replication
  • Encapsulating and Potting
  • Window Bushings
  • Custom and Standard Products
  • In House Mold Manufacturing
  • Small and Large Volume

Three Different Types of Cast Epoxy

Acid Anhydride

  • Recommended for both large and small electrical casting applications
  • Demonstrates excellent Mechanical Strength
  • 94V-0 – UL listed

Amine Cure

  • Demonstrates excellent Mechanical Strength
  • Suitable for use in Oil Filled Transformers
  • Recommended for use in casting or potting small electrical components, Transformer Bushings and Insulators.


  • Demonstrates excellent mechanical strength
  • Suitable for use with Oil-Filled Transformers
  • Recommended for use in casting or potting both small and large electrical components, Transformer Bushings and Insulators
  • Good weathering characteristics
Engineering Data
Name Acid Anhydride Amine Cure Cycloaliphatic
Color Grey Red or Grey Red or Grey
Hardness (Durometer) 92D 92D 92D
Tensile Strength, PSI 6,000 8,000 8,000
Flexural Strength, PSI 10,000 17,000 15,500
UL-RTI Rating 130º C NA NA
Dielectric Strength (0.125") 400 v/mil 400 V / Mil 420 V / Mil
Dielectric Constant @ 23º C, 103 Hz 4.0 4.0 4.0
Dissipation Factor @ 23º C, 10³ Hz 0.010 0.0193 0.010
Volume Resistivity @ 23º C, ohms-cm 2.0 x 1014 3.0 x 10¹4 5.0 x 10¹4
Material Meets UL-Flammability Rating 94 V-O (1/4" thickness) NA NA

Unless otherwise indicated, all properties published are based on tests performed on standard ASTM test samples and according to ASTM test methods. Values shown are for test samples made from production materials and they are believed to be conservative. No warranty is to be construed, however, in fabricated or molded form, parts may vary considerably from this standard test data. Where specific or unusual applications arise, test should be made on actual parts, and test procedures agreed upon between Haysite Reinforced Plastics and the customer.