FR5 rod is the solid round-bar form of FR-5 glass-epoxy laminate — a flame-retardant, high-temperature thermoset composite produced by impregnating woven fiberglass cloth with a brominated epoxy resin system and curing the layup under heat and pressure into rigid cylindrical stock. FR-5 sits between G-11 and FR-4 in the NEMA glass-epoxy family: it pairs the 180°C continuous-use rating of G-11 with the UL 94 V-0 flame performance of FR-4, making FR5 rod the right choice for high-temperature electrical insulators that also require self-extinguishing behavior.
FR5 rod delivers tensile strength of 35,000 psi, flexural strength of 60,000 psi, and compressive strength of 60,000 psi. Rockwell hardness reaches M110, and shear strength is approximately 18,000 psi. Water absorption over 24 hours is just 0.10%, supporting stable performance in humid service. The material carries a UL 94 V-0 flammability rating and a maximum continuous operating temperature of 355°F (180°C). These properties make FR5 rod the preferred choice for high-temperature electrical standoffs, transformer support rods, terminal posts, and Class H insulation hardware where flame retardancy is mandated.
Standards & compliance. FR5 rod conforms to NEMA LI-1 Grade FR-5 and is tested per ASTM D709. The flame-retardant rating is established under UL 94 V-0. Ready Plastics stocks FR5 rod in standard diameters available as cut-to-length pieces; request a custom cut or contact us for size availability.
Sister grades. For high-temperature service without flame-retardant requirements, G-11 glass-epoxy rod offers the same 180°C rating at lower cost. Where standard service temperatures (140°C) are sufficient and V-0 flame performance is required, FR-4 glass-epoxy rod is the industry-standard choice. For arc-resistant high-temperature service, see G-7 glass-silicone rod.
