G7 rod is the cylindrical round-bar form of NEMA G-7 glass-silicone laminate — a thermoset composite of woven fiberglass cloth and silicone resin, wound and cured under heat and pressure into dense, machinable round stock. The silicone resin matrix — rather than epoxy — gives G7 rod its exceptional thermal stability, allowing continuous service at temperatures up to 425°F (220°C) where glass-epoxy grades begin to soften. G7 rod is specified for turned insulating components in the most thermally demanding electrical and industrial applications.
G7 rod delivers 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). Water absorption over 24 hours is 0.20%. Arc resistance is excellent, a characteristic attributed to the silicone resin and critical for components exposed to high-voltage electrical arcing events.
Standards & compliance. G7 rod conforms to NEMA LI-1 Grade G-7 and is tested per ASTM D709. Its UL 94 V-0 self-extinguishing performance is inherent to the silicone resin system. Ready Plastics stocks G7 rod in standard diameters as cut-to-length pieces; contact us for size availability.
Step-down grades. When operating temperatures fall below 355°F, G-11 glass-epoxy rod provides higher compressive strength and better machinability at lower cost. For standard service up to 280°F, G-10 rod and FR-4 rod are the most economical glass-reinforced thermoset options.
