The use of currently available stress corrosion threshold data in design is discussed. Examples of service failures are detailed for parts which laboratory data have assisted in determining the cause of failure and resolution of the problem.

Stress corrosion test results of over 300 high-strength steel specimens are summarized. Specimens were tested by bend and axial tension loading and exposed to high humidity and alternate immersion in salt water. A comparison of 4340 and 300M alloys and the effect of product form, grain direction, part size, and stress concentration on the stress corrosion characteristics of these high-strength alloys are made. Methods for the use of these data and other published data are outlined. This use includes original design as well as analysis efforts to extend the service life of existing aircraft. Engineers' future needs for stress corrosion data point to the new-technology aluminum alloys and extended crack growth data under meaningful environments and loading conditions.