Laminates, Boards & Films
FR-4 Epoxy Insulation Board
Flame-retardant epoxy glass-cloth board, UL94 V-0, Class F
FR-4 is an alkali-free E-glass cloth impregnated with flame-retardant epoxy resin and laminated under heat and pressure. High mechanical strength, low water absorption and reliable flame-retardant performance.
Class F (155°C)UL94 V-0Thickness 0.5–150 mm
- Temperature class
- Class F (155°C)
- Thickness
- 0.5–150 mm
- Tg
- ≥120°C
- Colour
- Green
Request a quotation or a sample. Tell us thickness, width, temperature class, quantity and delivery form. We reply within one business day.
Technical data
| Property | Unit | Value |
|---|---|---|
| Material | — | Alkali-free E-glass cloth + flame-retardant epoxy |
| Normal thickness | mm | 0.5–150 |
| Density | g/cm³ | 1.80–1.95 |
| Thermal class | °C | 155 |
| Flammability rating | UL94 | V-0 |
| Glass transition temperature (Tg) | °C | ≥120 |
| Water absorption (24 h) | % | ≤0.10 |
| Flexural strength (vertical) | MPa | ≥340 |
| Tensile strength | MPa | ≥300 |
| Compressive strength | MPa | ≥350 |
| Interlaminar shear strength | MPa | ≥30 |
| Impact strength (Charpy) | kJ/m² | ≥35 |
| Rockwell hardness | M Scale | ≥110 |
| Temperature class | — | Class F (155°C) |
Values are typical values or ranges from our product data. Bulk supply is subject to the approved specification, sample and test report. If a parameter you need is not listed here, ask our engineers for the full test report for that grade.
Key features
- UL94 V-0 flame retardancy for fire-sensitive electrical structures.
- Low water absorption and high mechanical strength for dimensional stability.
- Cutting, drilling and CNC machining to drawing.
Applications
Transformer/motor insulation structures, switchgear barriers, electrical mounting boards and fixtures.
Switchgear & Electrical EquipmentDry-Type TransformersElectric Motors & Generators
Why it fits
Choose FR-4 over 3240 when the application needs documented flame retardancy, not just dielectric strength.
Ordering information
To receive a quotation, please confirm:
- Product and grade
- Thickness and width (and roll or sheet size)
- Temperature class
- Quantity and delivery form (roll / sheet / die-cut / machined)
- Destination port and required delivery date
For machined parts, attach a drawing in PDF, DWG or STEP format. Datasheets, COAs and batch test data are available on request.
Related materials
Often specified together
Send your specification
Our export team reviews the application, the process and the existing specification before recommending a construction.