G11 Sheet — Thicknesses, Sizes & Stock Forms
G11 sheet is flat laminate stock produced from NEMA G-11 glass-reinforced epoxy, a woven fiberglass and epoxy thermoset rated for continuous service to 180 °C (355 °F). Its combination of high flexural strength (75,000 psi), low moisture absorption (0.20%), and solid electrical insulation makes G11 sheet the go-to choice for fabricated bus bar insulation, high-voltage barrier boards, motor slot liners, and structural panels in power conversion equipment — wherever standard G10 sheet is not thermally adequate.
At a glance:
- Thickness range: 0.020" to 4.0"
- Standard sheet sizes: 36" × 48" and 48" × 96"
- Thickness tolerance: ±10% on thicknesses ≤ 0.062"; ±0.005" on thicker stock
- Material: NEMA G-11, woven glass-fabric/epoxy thermoset laminate
- Production method: Compression-molded flat laminate
- Color: Natural yellow-green
Standard Thickness Table
G11 sheet is stocked in the following standard gauges at Ready Plastics:
| Thickness | Sheet Size | Notes |
|---|---|---|
| 0.031" | 36" × 48" | Thin barrier/liner applications |
| 0.062" | 36" × 48" & 48" × 96" | Gaskets, slot liners |
| 0.093" | 36" × 48" & 48" × 96" | |
| 0.125" | 36" × 48" & 48" × 96" | High-volume standard thickness |
| 0.250" | 36" × 48" & 48" × 96" | Structural panel applications |
| 0.500" | 36" × 48" & 48" × 96" | Bus bar insulation, fixture plates |
| 0.750" | 36" × 48" | |
| 1.000" | 36" × 48" | Heavy structural or thermal barrier |
Custom thicknesses and slit widths are available on request.
Mechanical & Electrical Properties
| Property | Value |
|---|---|
| Tensile strength | 63,000 psi (430 MPa) |
| Flexural strength (LW, 0.125") | 75,000 psi (515 MPa) |
| Compressive strength | 37,000 psi (255 MPa) |
| Shear strength | 22,000 psi (150 MPa) |
| Bond strength | 2,200 psi (15 MPa) |
| Hardness (Rockwell M) | 112 |
| Izod impact strength (49 °C, LW) | 12.00 ft·lb/in |
| Specific gravity | 1.82 |
| Water absorption (24 hr) | 0.20% |
| Flammability rating | UL 94HB |
| Maximum continuous service temp | 180 °C (355 °F) |
Typical Applications
G11 sheet is waterjet-cut, CNC-routed, and punched into a wide range of flat insulation components:
- Bus bar insulation and phase barriers — rated for sustained high-temperature dielectric service
- Motor slot liners and winding separators — thin gauges conform to motor geometry; resist winding temperatures
- High-voltage terminal boards and mounting plates — dimensionally stable under cyclic thermal load
- Transformer barrier boards — low moisture absorption preserves creepage distances
- Structural support panels in power electronics enclosures
- Jig and fixture plates for elevated-temperature assembly and test environments
Machining G11 Sheet
G11 sheet is best cut with carbide router bits or a waterjet. Abrasive waterjetting produces clean edge finishes without heat-affected zones and is preferred for complex profiles. For straight cuts, a table saw with a carbide-tipped blade works well — use a fine-tooth blade and feed steadily to prevent chipping on the exit face. Drilling requires sharp brad-point or spiral-flute carbide drills; back the sheet with a sacrificial board to eliminate breakout. Fine grinding or sanding produces smooth surfaces suitable for bonding with epoxy adhesives.
Related
- G11 Glass Epoxy — Line Card
- G11 Rod — round bar for machined insulators and standoffs
- G11 Tube — hollow sections for coil forms and conduits
- G10 Sheet — standard-temperature glass-epoxy flat stock for moderate-temperature applications
- FR5 Sheet — flame-retardant high-temperature epoxy sheet, equivalent thermal class