Epoxy Resin Fiberglass Gaskets
Product Description
Product Detail
CNC-Machined Epoxy Glass Laminate Gaskets for Electrical Insulation and Mechanical Spacing
Kaxite Epoxy Resin Fiberglass Gaskets are machined from electrical-grade alkali-free E-glass woven fabric impregnated with epoxy resin, then laminated under heat and pressure. The standard G10 grade is the unfilled epoxy laminate; adding a flame retardant agent produces FR4 grade with UL 94 V-0 flame retardance. The laminate is rigid, dimensionally stable and machinable on standard CNC equipment, so it can be supplied as plain sheet, as a cut gasket, or as a fully machined part to drawing — with the bolt holes, radius, thickness and surface finish matched to the flange or assembly it is designed for. The material is used where the gasket must both carry a compressive mechanical load and hold off electrical voltage at the same time.
Two Grades — Pick the Right One for the Duty
Standard Epoxy Glass Laminate
Electrical-grade alkali-free E-glass fabric with epoxy resin binder, laminated under heat and pressure. No flame retardant is added, so it retains the highest mechanical strength and dielectric strength of the two grades.
- Best choice for: mechanical spacers, structural insulation, high-load backing plates
- Dielectric strength: 22 kV/mm at 0.5–1 mm
- Heat resistance: Martens 200°C or above
Flame-Retardant Epoxy Glass Laminate
Same E-glass fabric and epoxy resin system as G10, but with a flame retardant agent added during formulation. The result is the UL-listed FR4 grade with UL 94 V-0 rating and a self-extinguishing behaviour in the event of a fault.
- Best choice for: transformer, switchgear, motor and electronic apparatus
- Flame rating: UL 94 V-0, self-extinguishing
- Heat resistance: Martens 200°C or above
Where Epoxy Resin Fiberglass Gaskets Are Used
Insulating gaskets and spacers between the transformer core and clamp, and between the tank and cover, holding off voltage while carrying bolt load.
Insulation barriers, spacer washers and mounting plates in medium-voltage cubicles where arc and flame resistance are required.
Slot wedges, terminal board spacers, end-winding supports and washer stacks inside motor frames and stator housings.
Mounting spacers, standoff gaskets and back-plates under PCBs and power modules where heat resistance and flatness are both needed.
Insulation gaskets at the terminal ports, heater supports and access covers of industrial furnace equipment.
Insulating spacers and mounting plates in wafer handling and test equipment where flatness, cleanliness and temperature resistance are critical.
Radiation-resistant insulation gaskets and spacers used in the electrical and instrumentation assemblies of nuclear plants.
Moisture-resistant insulation gaskets and spacer plates in the electrical panels and sensors of hydroelectric equipment.
CNC-turned bushings, spacer rings, insulating washers and gasket profiles made to drawing from G10/FR4 sheet.
Machining Capability — What We Can Do to the Sheet
Technical Data Sheet
| Base material | Alkali-free E-glass fabric + epoxy resin |
| Standard grade | G10 (no flame retardant) |
| Flame retardant grade | FR4 · UL 94 V-0 |
| Specific gravity | 1.70 – 1.90 |
| Martens heat resistance | ≥ 200°C |
| Dielectric strength (0.5-1 mm) | 22 kV/mm |
| Dielectric strength (1.1-2 mm) | 20 kV/mm |
| Dielectric strength (>3 mm) | 18 kV/mm |
| Surface resistivity | ≥ 1.0 × 10^13 Ω |
| Volume resistivity | ≥ 1.0 × 10^13 Ω·cm |
| Dissipation factor Tan δ at 50 Hz | ≤ 0.05 |
| Bending strength (lengthwise / crosswise) | ≥ 3500 / 2900 kg/cm² |
| Tensile strength (lengthwise / crosswise) | ≥ 3000 / 2200 kgf/cm² |
| Impact strength (lengthwise / crosswise) | ≥ 150 / 100 kgf·cm/cm² |
| Bond strength | ≥ 580 kgf |
| Thickness range | 0.5 mm – 50 mm and above |
| Standard sheet size | 1020 × 1220 mm / 1220 × 2440 mm, or cut to size |
| Color | Natural yellow-green (G10) / Light green (FR4) |
| Customization | CNC machined to drawing, tolerance to ±0.05 mm |
| Documents | Download TDS and free sample available on request |
Request an Epoxy Resin Fiberglass Gasket Quotation
Send us the drawing or specify the thickness, outer diameter, inner diameter, hole pattern and quantity, and tell us whether you need G10 or FR4 grade. We reply within 24 hours with FOB price, lead time and a free sample offer for qualified buyers.
Frequently Asked Questions
It is a gasket machined from epoxy glass laminate sheet. The base is electrical-grade alkali-free E-glass woven fabric impregnated with epoxy resin and laminated under heat and pressure. The result is a rigid, dimensionally stable gasket that combines mechanical compressive strength with electrical insulation, used as a sealing or spacing element between metal flange faces or structural components.
G10 and FR4 use the same E-glass fabric and epoxy resin system. G10 is the unfilled version, retaining maximum mechanical and dielectric strength. FR4 has a flame retardant agent added during the resin formulation, producing a UL 94 V-0 self-extinguishing laminate. FR4 is the more commonly specified grade for transformer, switchgear and electronic applications.
Dielectric strength is 22 kV/mm at 0.5–1 mm thickness, 20 kV/mm at 1.1–2 mm, and 18 kV/mm above 3 mm. Martens heat resistance is 200°C or above, and density is 1.70–1.90 g/cm³. The dissipation factor Tan δ at 50 Hz is 0.05 or below and surface/volume resistivity is 1.0×1013 Ω or above.
Yes. We provide full CNC machining services including cutting, precise milling, drilling, tapping, turning, engraving, grinding and polishing. Send the drawing or sample and we will quote the finished part with tolerance control to ±0.05 mm for critical dimensions.
Thickness ranges from 0.5 mm to 50 mm and above. Standard sheet sizes are 1020 × 1220 mm and 1220 × 2440 mm, and both sheet stock and cut gaskets are available. Custom sizes are cut or machined to drawing on request.
Martens heat resistance is 200°C or above, which is the temperature at which the laminate begins to soften under a bending load. Continuous service temperature in insulation applications is typically specified below 130–150°C to maintain long-term mechanical properties, but short-term exposure to 180°C is common in transformer and switchgear assemblies.
Yes. Kaxite is an epoxy resin fiberglass gasket manufacturer and supplier in China, supporting wholesale orders, custom dimensions, private label packing and OEM service. Quotation is normally returned within 24 hours.
Yes. Free samples of the G10 / FR4 epoxy resin fiberglass gasket are offered to qualified buyers so thickness, flatness, dielectric properties and machined surface finish can be checked before a volume order.