määr, milleni säiluvad materjali kasulikud omadused tavatingimustes peale etteantud temperatuuril ja keskkonnas seisutamist ja tagasinaasmist tavatingimustele (vt kuumuskindlus)
the extent to which a material retains its useful properties at ambient air conditions, folowing its exposure to a specified temperature and environment for a specified time and its return to the ambient air conditions (compare: heat resistance)
