This part of ISO 25239 specifies the requirements for the specification and qualification of welding procedures for the friction stir welding (FSW) of aluminium. In this part of ISO 25239, the term “aluminium” refers to aluminium and its alloys. This part of ISO 25239 does not apply to friction stir spot welding. NOTE Service requirements, materials or manufacturing conditions can require more comprehensive testing than is specified in this part of ISO 25239.