ARTICLES of a wide variety of sizes and shapes can be produced easily by the sand-casting process. The advantage of simplicity and low cost offered by the sand-casting process for small numbers of identical parts is offset by certain inherent limitations which must be recognized clearly if it is to yield optimum results. The various methods of inspecting and controlling structural variations that affect the strength and serviceability of aircraft castings are described.It is recognized that the user of castings must rely to a considerable extent on the foundryman for careful inspection. Several direct tests worthy of consideration as final acceptance tests of quality, such as the proof test, radiography (X-ray examination), and the static breakdown test, are described. However, this discussion leads to the conclusion that there is not yet available a satisfactory direct method of predicting the normal life of an aircraft casting.The most pertinent evidence that the practices described in the paper are effective is the service record of aluminum-alloy castings. Maintenance and improvement of the service record depend largely on the continued and more complete cooperation of aircraft designers and engineers with the foundry personnel.