Fiberglass Epoxy Slot Wedge

Fiberglass Epoxy Slot Wedge | Motor Slot Insulation & Coil Retention Component

A Fiberglass Epoxy Slot Wedge is a critical insulating and mechanical component used in the stator or rotor slots of electric motors and generators. Its primary function is to secure winding coils firmly inside the slot, preventing displacement caused by electromagnetic forces, vibration, or centrifugal stress during motor operation.

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Fiberglass Epoxy Slot Wedge | Motor Slot Insulation & Coil Retention Component

In addition to mechanical retention, slot wedges provide electrical insulation, structural support, and controlled heat dissipation paths, contributing directly to motor reliability, efficiency, and service life. Depending on performance requirements, fiberglass epoxy slot wedges are manufactured from various high-performance laminated insulation materials suitable for different voltage, temperature, and efficiency classes.

These sheets maintain stable electrical properties in dry, humid, and oil-exposed environments, making them ideal for electrical equipment, heating systems, and high-temperature industrial applications.

Available Material Options

Material Grade	Description
FR4 (F881)	Glass epoxy laminate suitable for general electrical insulation applications
G11 (F882)	High-temperature glass epoxy laminate designed for elevated thermal performance
3240	Epoxy phenolic cotton cloth laminate offering good mechanical strength and machinability
GPO-3 (F622)	Polyester glass mat laminate with excellent arc resistance and flame retardancy
EPGC308 (F886)	High-strength epoxy glass cloth laminate for demanding electrical and mechanical conditions
Magnetic Slot Wedge (F897)	Loss-reducing magnetic composite designed to improve motor efficiency

Each material is selected based on thermal class, voltage level, mechanical stress, and overall efficiency requirements.

Product Details

Product Name

Fiberglass Epoxy Slot Wedge

Product Type

Motor Slot Insulation & Retention Component

Base Materials

FR4, G11, 3240, GPO-3, EPGC308, Magnetic Composite

Insulation Class

Class F / Class H

Operating Temperature

155 °C – 180 °C

Flame Retardancy

UL94 V-0 (material dependent)

Customization

Size, material, thickness as per motor design

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

Main Application Areas

Industrial Motors – Slot insulation for pumps, fans, and compressors
New Energy Vehicles (EVs) – Rotor slot wedges for traction motors
Wind Turbines – Stator slot fixation in large generators
High-Efficiency Motors (IE4 / IE5) – Magnetic slot wedges for loss reduction
High-Voltage Motors – GPO-3 and EPGC308 for enhanced insulation safety

Material Selection Guide