This part of ISO 25239 specifies a method for determining the capability of a fabricator to use the friction stir welding (FSW) process for the production of products of the specified quality. It specifies quality requirements, but does not assign those requirements to any specific product group. In this document, the term aluminium refers to aluminium and its alloys. This document does not apply to friction stir spot welding which is covered by the ISO 18785- series.