FR-4 Glass Epoxy Sheets

FR-4 Glass Epoxy Sheets | Flame-Retardant Electrical & Structural Laminate

FR-4 is a high-performance glass fabric reinforced epoxy laminate designed for applications requiring excellent electrical insulation, mechanical strength, and fire resistance. It is the flame-retardant grade of G-10, making it ideal for environments where safety, heat resistance, and electrical reliability are critical.

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FR-4 Glass Epoxy Sheets | Flame-Retardant Electrical & Structural Laminate

FR-4 sheets provide stable dielectric performance in both dry and humid conditions and maintain strong mechanical properties at elevated temperatures. Their high strength, rigidity, and resistance to chemicals make them suitable for use in electrical equipment, industrial machinery, and chemical processing environments.

In addition to industrial applications, FR-4 sheets are also used in household and commercial environments due to their durability, moisture resistance, and long service life.

Product Details

Product Name

Fiberglass cloth + Epoxy resin

Material

Woven Fiberglass + Epoxy Resin

Working temperature

≤ 170 °C

Color Options

Yellow

Thickness Range

Customizable

Size Format

Sheets, cut-to-size

Typical Applications

Switchgear, PCB, transformers, insulation parts

NEMA, IEC, Mil Spec Material Comparative Table
NEMA	IEC	Mil Spec	Resin	Substrate
NEMA G-10	EPGC 201, 21*	MIL-I-24768/2 GEE	Epoxy	Glass Cloth
NEMA FR4	EPGC 202, 23*	MIL-I-24768/27 GEE-F	Epoxy	Glass Cloth
NEMA G-11	EPGC 203, 22*	MIL-I-24768/3 GEB	Epoxy	Glass Cloth
NEMA FR5	EPGC 204	MIL-I-24768/28 GEB-F	Epoxy	Glass Cloth
—	EPGC 205	—	Epoxy	Glass Cloth
—	EPGC 306	—	Epoxy	Glass Cloth
—	EPGC 307	—	Epoxy	Glass Cloth
—	EPGC 308	—	Epoxy	Glass Cloth
—	EPGC 309	—	Epoxy	Glass Cloth
—	EPGC 310	—	Epoxy	Glass Cloth
—	EPGC 311	—	Epoxy	Glass Cloth
—	EPGM 203	—	Epoxy	Glass Mat
—	EPPC 301	—	Epoxy	Polyester Cloth
NEMA G-5	MFGC 201, 20*	MIL-I-24768/8 GMG	Melamine	Glass Cloth
NEMA G-9	MFGC 201	MIL-I-24768/1 GME	Melamine	Glass Cloth
NEMA C	PFCC 201, 23*	MIL-I-24768/16 PBM	Phenolic	Cotton Cloth
NEMA CE	PFCC 202, 22*	MIL-I-24768/14 FBG	Phenolic	Cotton Cloth
NEMA L	PFCC 203	MIL-I-24768/15 FBI	Phenolic	Cotton Cloth
NEMA LE	PFCC 204, 21, 24	MIL-I-24768/13 FBE	Phenolic	Cotton Cloth
NEMA X	PFCP 201, 21*	MIL-I-24768/12 PBM	Phenolic	Cellulosic Paper
NEMA XP	PFCP 201	MIL-I-24768/19 PBM-P	Phenolic	Cellulosic Paper
NEMA XXX	PFCP 204	MIL-I-24768/10 PBE	Phenolic	Cellulosic Paper
NEMA XX	PFCP 202, 23*	MIL-I-24768/11 PBG	Phenolic	Cellulosic Paper
NEMA XXP	PFCP 203	MIL-I-24768/21 PBG-P	Phenolic	Cellulosic Paper
NEMA XXXP	PFCP 204	MIL-I-24768/22 PBE-P	Phenolic	Cellulosic Paper
NEMA XPC	PFCP 207	MIL-I-24768/20 PBM-C	Phenolic	Cellulosic Paper
NEMA G-3	PFGC 201, 21*	MIL-I-24768/18 GPG	Phenolic	Glass Cloth
NEMA GPO-1	UPGM 201	MIL-I-24768/4	Polyester	Glass Mat
NEMA GPO-2	UPGM 202	MIL-I-24768/5	Polyester	Glass Mat
NEMA GPO-3	UPGM 203	MIL-I-24768/6	Polyester	Glass Mat
—	UPGM 205	—	Polyester	Glass Mat
—	PIGC 301	—	Polyimide	Glass Cloth
NEMA G-7	SIGC 201, 21*	MIL-I-24768/17 GSG	Silicone	Glass Cloth

Note:
1 – Comparable grades can vary slightly in specification based on test methods and thickness.
* Indicates IEC tube standard.

Applications of our Products

Generator Construction

Hydroelectric generators
Turbine generators
High voltage motors

Transformer And Coil Construction

Small transformer
Choke coils
Oil-filled substation transformers
Dry-type transformer
Cast resin transformer
Cast resin measuring transformers
Magnet coils for superconducting

Motor Constructions

DC motors
Single-phase AC motor (Up to 500 KW)
Traction motors
DC electrical machines
Low voltage motors (Larger than 500 KW)

Capacitor Construction

Power capacitor

Electrical Vehicles

Electrical vehicle motors
Batteries
Electronic control units (ECUs)

High Temperature Applications

Oil & Gas industry
Metallurgy & Chemical industries
Aerospace

Miscellaneous

Rectangular section wires
Automatic circuit breakers
Sensors & Communication systems
Heaters & Heating systems
Switchgears
Domestic appliances
Industrial electronics

G10 VS G11 VS FR4 VS FR5

Distinguishing Features of FR4 vs. G10:

Distinguishing Features of FR5 vs. G11:

Mechanical Strength :

Both FR4 and G10 showcase exceptionally high mechanical strength.

Color :

G11/FR5 exhibits a distinctive yellow-green to amber color.

Temperature Performance :

Both provide heat resistance up to 155°C. FR4 offers superior operating temperatures and enhanced mechanical strength at elevated temperatures compared to G10.

Temperature Performance :

Both offer heat resistance up to 200°C. FR5 surpasses G11 with higher operating temperatures and superior mechanical strength at elevated temperatures.

Dielectric Properties :

Both demonstrate commendable dielectric loss and electric strength properties in both wet and dry conditions.

Dielectric Properties :

Just like other Glass Epoxy Laminates both demonstrate commendable dielectric loss and electric strength properties in both wet and dry conditions.

Notable Distinction :

FR4 is the fire-retardant grade of G10. While FR4 can seamlessly substitute G10, the reverse is not recommended. Opt for FR4 in applications demanding fire retardancy.

Noteworthy Difference :

G11 lacks fire retardancy, whereas FR5 is specifically a FR grade of G11. FR5 can be an effective substitute for G11, but G11 should not replace FR5 in applications requiring fire retardancy.