G-11 High-Temperature Glass Epoxy — Sheet

G11 sheet is the flat-panel form of NEMA G-11 glass-epoxy laminate — a high-temperature thermoset composite of woven glass fabric impregnated with a high-heat epoxy resin system, laminated under heat and pressure. G-11 is engineered specifically for service conditions that exceed the thermal limits of G-10 and FR-4, delivering exceptional electrical insulation and mechanical strength at continuous temperatures up to 355°F (180°C). It is closely related to FR-5 (its flame-retardant counterpart) and is specified when elevated temperature performance takes priority.

G11 sheet delivers tensile strength of 63,000 psi, an impressive flexural strength of 75,000 psi, and compressive strength of 37,000 psi. Rockwell M112 hardness and 22,000 psi shear strength reflect the material's structural integrity at operating temperature. Water absorption over 24 hours is just 0.20%. The 94HB flammability rating and maximum continuous operating temperature of 355°F (180°C) — significantly higher than G-10's 280°F limit — make G11 sheet the right choice for panels and insulators in high-heat industrial and electrical environments.

Standards & compliance. G11 sheet conforms to NEMA LI-1 Grade G-11 and is tested per ASTM D709. Ready Plastics stocks G11 sheet in standard thicknesses; contact us for dimensions and custom-cut availability.

Sister grades. G-10 glass-epoxy sheet is the lower-cost standard-temperature option, rated to 280°F (140°C). FR-4 glass-epoxy sheet adds UL 94 V-0 flame retardancy within the same temperature range. For the most demanding thermal environments — continuous service above 355°F — G-7 glass-silicone sheet withstands up to 425°F (220°C).