304 stainless steel samples were oxidized in pure flowing oxygen at 800-degrees-C for 20 h, then furnace cooled, either directly to room temperature or to an intermediate temperature, held at that temperature f or 2 4 h and then furnace cooled to room temperature. Cracking and spalling of the oxide scale were monitored by acoustic emission (AE) technique throughout the experiment. Only a few AE events were observed during the isothermal exposure and during furnace cooling to ca. 300-degrees-C. A significant number of events was observed starting at ca. 300-degrees-C and during further cooling, with a maximum rate at ca. 150-degrees-C for continuous furnace cooling. If the cooling was interrupted at some temperature < 300-degrees-C, the scale fracture process stopped, but then resumed on further cooling. To explain this behavior, it is hypothesized that the stress intensity varies locally within the scale, e.g., due to local variations of stress values or to the variation of the size of flaws across the sample. When the local stress intensity reaches a critical value, K(c), cracks propagate rapidly. An analysis of AE data shows that the conditions for scale cracking follow a log normal distribution with respect to average scale stress.