G11 material is a high-temperature woven-fiberglass/epoxy thermoset laminate classified under NEMA LI-1 Grade G-11. It belongs to the glass epoxy family and represents the upper end of the non-flame-retardant glass epoxy grades. G11 material uses a resin system with a higher glass transition temperature than G-10, enabling reliable performance in applications where standard glass epoxy laminates would soften or lose mechanical integrity under sustained heat.
G11 delivers 63,000 psi tensile strength, 75,000 psi flexural strength, and 37,000 psi compressive strength at a Rockwell M112 hardness. Shear strength reaches 22,000 psi and water absorption over 24 hours is only 0.20%. Maximum continuous service temperature is 355°F (180°C) — 75°F higher than G-10. This g11 sheet performance profile makes it a preferred choice for motor slot wedges, coil forms, transformer insulation, and precision-machined structural parts exposed to sustained elevated temperatures. The g11 laminate is also specified in applications requiring good chemical resistance alongside high heat performance.
Standards. G11 meets NEMA LI-1 Grade G-11, with test methods per ASTM D709. The grade carries a UL 94HB flammability rating — for an equivalent high-temperature grade with flame-retardant classification, specify FR-5. NEMA G11 is the mechanical (non-FR) counterpart to FR-5, sharing nearly identical property values.
Grade comparisons. Step down to G-10 when continuous service stays below 140°C and cost efficiency is the priority. Choose FR-5 when the same thermal performance is required alongside a flame-retardant rating. For standard electrical insulation with a V-0 flame requirement, FR-4 covers most applications up to 140°C. Ready Plastics stocks G11 material in sheet and rod forms — contact us for available dimensions and datasheet.
