G10 Epoxy sheet– Common Thicknesses & Selection Guide

Time: 11-04 2025 Auther: Xujue Electrical

Introduction to G10 Epoxy sheet G10 epoxy sheet is a high-strength fiberglass-reinforced epoxy laminate, known for ...

Introduction to G10 Epoxy sheet

G10 epoxy sheet is a high-strength fiberglass-reinforced epoxy laminate, known for its excellent mechanical strength, electrical insulation properties, low moisture absorption, and strong oil resistance. It is widely used in electrical, mechanical, and industrial applications.what is the typical thickness of G10 epoxy board? Today, Xujue Electrical will give you a detailed guide on common G10 epoxy board thicknesses and how to select them.

g10 epoxy sheet factory

1.Recommended Thickness by Application (Quick Selection Table)

Application / Part	Recommended Thickness (mm)	Reason
Thin insulation sheets, light-duty separators	0.5–1.2 mm	Flexible, lightweight, non-load-bearing insulation
Internal isolation plates	1.6–2.0 mm	Basic rigidity + electrical insulation
Equipment structural insulation parts	3–6 mm	Higher mechanical strength and stability
Transformer terminal boards / motor end plates	5–10 mm	Withstand bolt torque, high dielectric strength
HV insulating barriers, phase separators	8–20 mm	Higher creepage distances and rigidity
Load-bearing insulating blocks	10–30 mm	Strong bending and compressive strength
Large structural insulation components	20–50 mm	For large machines and oil-immersed environments

2. When to Choose G10 Instead of FR4

Better mechanical strength
More stable dielectric properties
Superior oil resistance → suitable for transformers
Higher thermal rating (commonly Class F / 155°C)
However, G10 is not flame-retardant (unlike FR4).
If UL94 V-0 is required, choose FR4 or G11 V-0 grade.

3. Selection Guidelines (Engineering Steps)

Operating environment
Oil-immersed, high-humidity, high-temperature → choose G10
Flame-retardant requirement → avoid G10
Mechanical load
Load-bearing components → 5 mm, 10 mm, 20+ mm depending on force
Electrical insulation requirements
Higher voltage → use thicker plates (8–20 mm)
Processing method
CNC machining → thick plates OK
Punching → ≤2 mm only
Tolerance & surface finish
Common thickness tolerance: ±0.1 mm
High precision: ±0.05 mm

4. Fast Selection for Transformer Applications

Transformer Component	Recommended Thickness	Reason
Terminal boards	5–10 mm	Mechanical load + insulation
Phase separators	6–12 mm	Mechanical rigidity + creepage distance
High-voltage insulation barriers	10–20 mm	High dielectric & mechanical strength
Structural support blocks	10–30 mm	Strong load-bearing performance
Oil-immersed insulation parts	8–20 mm (G10 recommended)	Excellent oil resistance

5.Contact the manufacturer

If you are looking for G10 epoxy fiberglass sheets, please contact Xujue Electrical and provide the product specifications, thickness and purpose you need, you can get detailed product information and quotation, and also send samples free of charge

Leave us a message to get quotation and sample!

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