ISO 26909:2009 specifies terms and definitions commonly used in the metal springs industry. Specifically, these terms appear in technical product documentation. Heat-treatment and surface-treatment terms pertinent to springs are included. Terms in ISO 26909:2009 are grouped into the following seven categories: a) general features of springs; b) application of springs in machinery and engineering; c) layouts and nomenclature of springs; d) specification requirements; e) design and calculation; f) manufacturing and processing; g) testing and inspection.