maximum temperature for fiberglass
High Heat Resistance. Fiberglass cloth has excellent heat resistance at relatively low cost. Fiberglass cloth retains approximately 50% of room temperature tensile strength at 700Â°F (371Â°C); approximately 25% at 900Â°F (482Â°C); with a softening point of 1555Â°F (846Â°C) and a melting point of 2075Â° F (1121 Â°C). Fire Resistance.