FSG is produced in a complex and oustanding process using a unique gravity bending method. Cut-to-size, drilled and edge-worked flat glass sheets are heated in a special tempering furnace to about 700°C and shaped after exiting the heating zone. They are then cooled rapidly by cold air blown onto the bent glass. This results in the two outer surfaces contracting and solidifying before the interior, which induces permanent compressive stresses into the surfaces of the glass, effectively increasing the strength of the glass and keeping it in the new shape. The interior of the glass naturally balances the compressive stress surface layers by being under tensile stress. These properties result in the increased strength and safe breakage characteristics of thermally toughened glass. When the central tensile section of the glass is ruptured, the stress is explosively released, producing the fracture characteristics of small, relatively harmless fragments.

To assure the highest quality possible, FSG curved single-pane safety glass is subject to continuous process monitoring and quality control. However, the toughening and bending process of FSG can introduce a degree of optical imperfection into the glass in the form of Anisotropies and bow or roller wave distortions. These are due to physical restrictions and / or are inherent to the manufacturing principle and cannot be considered as a defect.