Past experiments to demonstrate the feasibility of using acoustic emission analysis to detect stress corrosion crack growth during proof testing have been performed for Type 304 stainless steel. There was little or no acoustic emission at operating stress levels, where the operating stress intensity factor was 58.0 ksi ., but emission increased to a maximum at the proof stress intensity factor of 73.0 ksi . for specimens that were given stress relief anneal and at a proof stress intensity factor of 102.0 ksi . for specimens heat treated at higher temperatures.