Epoxy Fiberglass Sheets are a critical material in industrial and electrical engineering thanks to their exceptional mechanical strength, thermal stability, and electrical insulation properties. Different models are engineered with specific attributes to meet diverse manufacturing and engineering demands.
This guide provides a detailed technical comparison of five widely used grades—FR4, FR5, 3240, G10, and G11—to help engineers and procurement specialists select the optimal material for their applications.
FR4
A widely recognized epoxy fiberglass laminate known for its high strength-to-weight ratio and excellent electrical insulation. It resists moisture and tolerates moderate heat, making it the standard choice for printed circuit boards (PCBs), electrical insulation components, and equipment enclosures.
FR5
An enhanced thermal resistance version of FR4, designed to withstand higher operating temperatures without performance degradation. Common in aerospace and automotive applications where heat stability is essential.
3240
A high-performance epoxy fiberglass sheet combining the strengths of FR4 and FR5. It offers excellent mechanical strength and high thermal stability, suitable for heavy-duty electrical insulation and load-bearing structural parts in demanding environments.
G10
A glass epoxy laminate with high strength and very low moisture absorption, making it ideal for humid or marine environments. Unlike FR4, it is non-flame-retardant. Commonly used in military, aerospace, and mechanical applications.
G11
An advanced high-temperature grade of G10, featuring very high thermal resistance, excellent mechanical performance, and top-tier electrical insulation. Ideal for high-heat electrical systems and critical structural components in aerospace and defense sectors.
Model |
Thermal |
Mechanical |
Electrical |
Moisture |
FR4 |
Moderate |
Good |
Excellent |
Low |
FR5 |
High |
Good |
Excellent |
Low |
3240 |
High |
Excellent |
Excellent |
Low |
G10 |
Moderate |
High |
Good |
Very Low |
G11 |
Very High |
Excellent |
Excellent |
Low |
FR4 → PCBs, electrical housings, insulation panels for industrial electronics.
FR5 → Aerospace components, automotive electronics, high-temperature enclosures.
3240 → Heavy-duty electrical insulation boards, structural frames in high-performance equipment.
G10 → Military gear, aerospace interiors, marine-grade mechanical parts.
G11 → High-temperature electrical insulation, aerospace structural supports, defense-grade systems.
Selecting the right epoxy fiberglass sheet involves balancing thermal resistance, mechanical strength, electrical performance, and environmental factors such as moisture.
Choose FR4 for standard electronics and general-purpose insulation.
Choose FR5 when higher heat resistance is necessary.
Choose 3240 for superior mechanical and thermal stability in heavy-duty environments.
Choose G10 for applications requiring low moisture absorption and high strength without flame-retardancy.
Choose G11 for critical high-temperature and high-strength applications.
In conclusion, the choice of epoxy fiberglass sheet model depends on the specific requirements of the application, including thermal resistance, mechanical strength, and moisture absorption. Understanding the differences between FR4, FR5, 3240, G10, and G11 is crucial for selecting the appropriate material for optimal performance in various industrial settings. Each model offers unique advantages that cater to the diverse needs of modern engineering and manufacturing.