High Strength High Temperature Fiberglass CFF™ (Continuous Filament Fabrication) Spools. High Strength, High Temperature (HSHT) Fiberglass is a material uniquely designed for users who need strong parts in higher temperature environments (over 105°C, with a heat deflection point of 140°C). This capability is critical for the automotive and aerospace industries where load bearing parts are continually expected to withstand higher temperatures.