If an inclusion is located in the central tension zone of the glass, this expansion creates enough internal stress to shatter the pane without any external impact. 2. The Heat Soak Process (HST)
: The glass must be held at the target temperature for a minimum duration of 3. Technical Specifications and Tolerances din en 14179-1
The economic and practical implications of DIN EN 14179-1 are significant. The heat soak process adds cost—the energy, time, and handling required for the secondary heating cycle can increase the price of toughened glass by 10-30%. Furthermore, the process can result in a yield loss, as panes containing NiS break during testing. Consequently, not all toughened glass is heat soaked; it is typically specified only for "safety-critical" applications. The standard provides a clear contractual and legal framework: if a product is sold as "heat soaked glass to EN 14179-1," the manufacturer is legally bound to perform the test and provide documentation. For architects and engineers, specifying this standard is a powerful risk management tool. If an inclusion is located in the central
: The primary goal is to reduce the "residual risk" of spontaneous breakage caused by critical nickel sulfide (NiS) inclusions Key Identification Consequently, not all toughened glass is heat soaked;