Stress corrosion cracking is a phenomenon where a synergistic action of corrosion and tensile stress leads to brittle fracture of normally ductile materials at generally lower stress levels. During stress corrosion cracking, the material is relatively unattacked by the corrosive agent (no general corrosion, only localized corrosion), but fine cracks form within it. This process has serious implications on the utilisation of the material because the applicable safe stress levels are drastically reduced in the corrosive medium. Season cracking and caustic embrittlement are two stress corrosion cracking processes which affected the serviceability of brass cartridge cases and riveted steel boilers respectively.