By the adoption of the International Standards ISO 15841 and ISO 27020 into the German body of standards as DIN EN ISO 15841 as well as DIN EN ISO 27020, terms and definitions, requirements and test methods for archwires and attachments for orthodontic appliances are uniformly defined worldwide. With respect to the previous national standards DIN 13971 and DIN 13971-2 however, the tolerances specified in these documents have not been incorporated. These dimensions are important as in clinical applications brackets and archwires for orthodontic appliances are only compatible when the specified dimensions and tolerances are met. For this reason Working Committee NA 014-00-18 AA "Kieferorthopädische Produkte" ("Orthodontic materials") has decided to continue to specify the dimensions and their tolerances in this International Standard. This standard applies for the attachments brackets and tubes as well as for wires used in fixed and removable orthodontic equipment. The standard specifies dimensions and their tolerances. At DIN the responsible Working Committee is NA 014-00-18 AA "Kieferorthopädische Produkte" ("Orthodontic materials") of NADENT.