Abstract: Some brass angular valves used for kitchens produced by a factory cracked after use for about 4 months. Means, such as macroscopic and microscopic fracture analysis, chemical composition analysis, hardness testing, metallographic inspection, and ammonia test, were used to investigate cracking reasons of the brass angular valves. The results show that:the failure of angular valves resulted from the stress corrosion; the stress corrosion cracking was mainly caused by too big assembling stress of angular valves.