G11 · flame-retardant grade
G11-FR5
Properties of the FR5 condition, compared with the other G11 grades.
Pick when the same high-temperature G-11 mechanical/electrical performance must also carry a UL 94 V-0 flame rating (electrical enclosures, PCB substrates, rail/aerospace interiors).
What is G11-FR5?
G11-FR5 is G11 in the FR5 grade — pick when the same high-temperature G-11 mechanical/electrical performance must also carry a UL 94 V-0 flame rating (electrical enclosures, PCB substrates, rail/aerospace interiors). G11-FR5 has a tensile strength of 330 MPa (47.9 ksi), stronger than 55% of composite grades. Elongation at break is 1.8% and the elastic modulus is 22 GPa (3.19 Msi). G11-FR5 has a density of 1.85 g/cm³ (0.0668 lb/in³), heavier than 65% of composite grades. Its glass-transition temperature is 150°C (302 °F). Epoxy Matrix is the default condition FabDigit quotes; FR5 is available on request or by drawing note.
Advantages
- Low moisture uptake — 0.1%, better than 85% of composite grades
G11-FR5 properties
Typical room-temperature values for G11-FR5 — 11 properties are specific to this condition; the rest are grade-level values shared by every G11 grade. Each bar shows where the value sits among the composite grades in FabDigit's library — further right is higher.
Physical4
G11-FR5 has a density of 1.85 g/cm³ (0.0668 lb/in³), heavier than 65% of composite grades. Its glass-transition temperature is 150°C (302 °F).
Mechanical12
G11-FR5 has a tensile strength of 330 MPa (47.9 ksi), stronger than 55% of composite grades. Elongation at break is 1.8% and the elastic modulus is 22 GPa (3.19 Msi).
Thermal7
G11-FR5 is rated for continuous service to 170°C (338 °F). It conducts heat at 0.33 W/m·K (0.191 BTU/hr·ft·°F), worse than 53% of composite grades. Thermal expansion is 14 µm/m·K (7.78 µin/in·°F).
Electrical7
G11-FR5 is an electrical insulator with a dielectric strength of 16 kV/mm (406.4 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 76% of composite grades. UV resistance is fair.
Sustainability4
Producing a kilogram of G11-FR5 takes about 110 MJ of energy and emits 7 kg of CO₂ — less than 61% of composite grades. Typical recycled content is 0%.
Manufacturability2
G11-FR5's machinability is fair (45/100, better than 64% of composite grades).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other G11 grades and fills
G11 is also supplied in 1 other condition. The full side-by-side table is on the G11 overview.
- Epoxy MatrixDefaultDefault choice for high-temperature structural or electrical insulation parts where no flame rating is required.340 MPa tensile
- FR5Pick when the same high-temperature G-11 mechanical/electrical performance must also carry a UL 94 V-0 flame rating (electrical enclosures, PCB substrates, rail/aerospace interiors).330 MPa tensile
Working with G11-FR5
Is G11 easy to machine?
Machine dry with sharp carbide or PCD tooling, high speed / moderate feed, backup plates to stop edge delamination; glass dust is abrasive and requires extraction and respiratory protection.
Can G11 be welded?
Not weldable — thermoset laminate; join by bolting with washers/oversized holes or by epoxy/structural adhesive bonding of abraded, solvent-cleaned surfaces.
Can G11 be formed, bent or molded?
Supplied as flat sheet, rod and tube only; no post-forming — parts must be machined or laminated to shape during the original press cure.
What surface finishes work on G11?
Cannot be plated or anodized; edges are sanded and can be sealed with epoxy or polyurethane varnish for moisture and UV protection, screen printing and painting need abrasion plus adhesion primer.
G11 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| E-glass woven fabriccontinuous filament woven glass cloth, typically style 7628/7629 or heavier | 55 – 68 | 62 |
| epoxy resin (high-temperature cure systemultifunctional/anhydride- or dicy-cured epoxy for elevated-temperature strength retention | ≥ 32 (balance) | — |
G11-FR5 — frequently asked
What is G11-FR5 used for?
G11-FR5 is typically used for transformer and coil insulation parts, terminal boards and standoffs, high-temperature PCB substrates (FR5), aerospace electrical insulation, motor slot wedges and coil supports and switchgear insulating panels. In short: high-temp electrical laminate.
What is the tensile strength of G11-FR5?
G11-FR5 has a typical tensile strength of 330 MPa (47.9 ksi) — stronger than 55% of composite grades. Strength varies by condition: see the 2 listed tempers.
Is G11-FR5 easy to machine?
Reasonably — machinability is rated fair (45/100, better than 64% of composite grades). Machine dry with sharp carbide or PCD tooling, high speed / moderate feed, backup plates to stop edge delamination; glass dust is abrasive and requires extraction and respiratory protection.
Can G11-FR5 be welded?
Not weldable — thermoset laminate; join by bolting with washers/oversized holes or by epoxy/structural adhesive bonding of abraded, solvent-cleaned surfaces.
What surface finishes work on G11-FR5?
Cannot be plated or anodized; edges are sanded and can be sealed with epoxy or polyurethane varnish for moisture and UV protection, screen printing and painting need abrasion plus adhesion primer.
Can G11-FR5 be formed, bent or molded?
Supplied as flat sheet, rod and tube only; no post-forming — parts must be machined or laminated to shape during the original press cure.
What is the maximum service temperature of G11-FR5?
G11-FR5 is rated for continuous use to about 170°C (338 °F), and briefly to 220°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in G11-FR5?
Yes — G11-FR5 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- NEMA LI 1 — Industrial Laminated Thermosetting Products — NEMA (1998)
- ASTM D709 — Standard Specification for Laminated Thermosetting Materials — ASTM (2017)
- MIL-I-24768/3 (GEB) — Plastic Sheet, Laminated, Thermosetting, Glass Cloth, Epoxy Resin — US DoD (1994)
- Engineered Materials Handbook, Vol. 1: Composites — ASM International (1987)
- Garolite / G-11 & FR-5 glass-epoxy laminate datasheets — Professional Plastics / Current Inc. (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.