G7 sheet is the flat-panel form of NEMA G-7 glass-silicone laminate — a thermoset composite produced by impregnating woven fiberglass cloth with silicone resin and curing under heat and pressure. The silicone binder system distinguishes G-7 from the glass-epoxy family (G-10, FR-4, G-11), providing exceptional thermal stability at temperatures where epoxy-based laminates begin to degrade. G7 sheet is the material of choice when flat insulating panels must survive continuous operating temperatures up to 425°F (220°C).
G7 sheet provides tensile strength of 45,000 psi, flexural strength of 25,000 psi, and shear strength of 17,000 psi. The material carries a UL 94 V-0 flammability rating and a maximum continuous operating temperature of 425°F (220°C) — the highest of any NEMA laminate in the Ready Plastics line. Water absorption over 24 hours is 0.20%. Arc resistance is excellent, making G7 sheet a preferred material in high-voltage insulation applications where electrical arcing is a design concern.
Standards & compliance. G7 sheet conforms to NEMA LI-1 Grade G-7 and is tested per ASTM D709. Its UL 94 V-0 self-extinguishing rating is standard. Ready Plastics stocks G7 sheet in standard thicknesses; contact us for dimensions and custom-cut availability.
Step-down grades. When the application temperature is below 355°F, G-11 glass-epoxy sheet delivers higher flexural and compressive strength at lower cost. For standard industrial temperature ranges up to 280°F, G-10 sheet or FR-4 sheet are the most economical choices.
