Glass Epoxy Overview

Glass epoxy is a composite material that offers exceptional electrical and thermal insulation. It is ideal for applications requiring resistance to high temperatures, mechanical strength, and dimensional stability. Atlas Fibre machines and stocks several types of glass epoxy, including G-10, G-11, and FR-4. Learn more about our glass epoxy sheeting and its applications.

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Types of Glass Epoxy Material

Glass epoxy material consists of an epoxy resin combined with a glass-fiber matrix. Different types of glass epoxy have varying levels of fire retardance, making certain types more suitable for some applications than others. Learn more about the materials Atlas Fibre has available.


FR-4 glass epoxy is a laminate sheet made from a woven fiberglass substrate and a flame-retardant epoxy resin. Common applications for FR-4 include insulation in humid and dry conditions and various mechanical and electrical uses. FR-4 is an excellent generalist material that exhibits reliable and cost-effective electrical and mechanical performance for most use cases.

FR-4 has excellent insulation resistance and mechanical strength and good fabricating characteristics.


FR-5 glass epoxy is similar to FR-4 but is designed for higher operating temperatures. It is able to keep its insulating and mechanical properties up to an operating temperature of 150 degrees Centigrade (FR-5). It maintains its properties in dry and humid conditions. Because of its better glass transition temperature coupled with its flame retardant nature, FR-5 glass epoxy is often the preferred material for automobile producers.


G-10 glass epoxy is the non flame retardant version of FR-4, made of a halogen-free epoxy resin binder and woven fiberglass substrate. It has excellent electrical insulation qualities and high mechanical strength in both wet and dry conditions. G-10 is easy to fabricate and ideal for use in cryogenic and structural applications, particularly when halogenated compounds are unwanted.


G-11 glass epoxy shares many similarities with G-10. It’s made from a halogen-free epoxy resin and woven fiberglass substrate. It also offers excellent mechanical strength at high temperatures and good insulative strength in wet and dry conditions.

Compared to G-10, G-11 glass epoxy can withstand higher temperatures. It is also slightly better at insulating than G-10. G-11 resists dimensional change, flow and chemicals. It has low moisture absorption. G-11 comes in two varients. One designed for an operating temperature of 150 degrees Centigrade (Class F) and one designed for an operating temperature of 180 degrees Centigrade (Class H). When specifying G-11, please ensure you’re specifying the grade suitable for your intended operating environment.

Glass Epoxy Shapes

Atlas Fibre is the primary supplier of thermoset composite laminate in North America. We have more than $8 million in raw inventory at our Illinois warehouse. Our other facilities house an additional $4 million of materials. The glass epoxy laminate we offer is available in several shapes:

  • Glass epoxy tubes: We have a selection of glass epoxy tubes available in a range of diameters. We can cut the tubes to length based on your project needs.
  • Epoxy glass sheets: Laminate glass epoxy sheets are available in several thicknesses and dimensions. We can supply sheets in the correct size for your application.
  • Glass epoxy rods: While glass epoxy tubes have an opening in the center, glass epoxy rods are solid. We can produce glass epoxy rods in a range of lengths and diameters.

Uses for Glass Epoxy Resin

Glass epoxy has multiple applications thanks to its high tolerance for heat and excellent insulative properties. Some uses for glass epoxy laminates include:

  • Sealing and gasket components
  • Heating elements
  • Static electrical insulator
  • Insulators in induction systems
  • Use in welding
  • Furnaces

Get a Quote for Glass Epoxy Today

Atlas Fibre has more than 60 years of experience machining glass epoxy and supplying stock glass epoxy shapes. We can work with you to help you determine which type of glass epoxy material will best serve your project, providing the best wear prevention, corrosion resistance, and strength. To learn more about our materials and capabilities, contact us for a quote today.