The opening behaviour of bursting discs varies depending on the type of bursting disk in use. STRIKO bursting discs made of metal, for which the design specifies a defined opening, react fragment-free. Metal rupture discs open in an undefined manner. Parts of the bursting foil may be carried away here. STRIKO bursting discs made of graphite always open with fragmentation due to the material property. When calculating the necessary nominal sizes the opening behaviour directly influences the available flow cross-section of the bursting disc.