Heat Soak Test (HST)

This advanced quality control process for tempered glass involves heating it in a specialized, precisely calibrated furnace according to a strictly defined temperature and time cycle. The test aims to identify panes containing internal stresses or micro-inclusions (e.g., nickel sulfide), which could lead to spontaneous glass breakage after installation. During the HST process, potentially defective panes are destroyed under controlled production conditions, eliminating the risk of their use in the finished project.