This International Standard specifies the size pairing of double ended wrenches. It applies not only to flat wrenches for nuts but also to all wrenches with two fixed ends for screws and nuts, such as socket wrenches.
DIN ISO 1085:2018 Referenced Document
DIN ISO 272:1979 Fasteners; Width across Flats for Hexagon Products
DIN ISO 691:2007 Assembly tools for screws and nuts - Wrench and socket openings - Tolerances for general use (ISO 691:2005) English version of DIN ISO 691:2007-04
ISO 1703:2005 Assembly tools for screws and nuts - Designation and nomenclature
ISO 272:1982 Fasteners; Hexagon products; Widths across flats
ISO 691:2005 Assembly tools for screws and nuts - Wrench and socket openings - Tolerances for general use
DIN ISO 1085:2018 history
2018DIN ISO 1085:2018-12 Assembly tools for screws and nuts - Double-ended wrenches - Size pairing (ISO 1085:2016)
1970DIN ISO 1085 E:2018-06 Assembly tools for screws and nuts - Double-ended wrenches - Size pairing
2018DIN ISO 1085:2018 Assembly tools for screws and nuts - Double-ended wrenches - Size pairing (ISO 1085:2016)
2007DIN ISO 1085:2007 Assembly tools for screws and nuts - Double-ended wrenches - Size pairing (ISO 1085:1999) English version of DIN ISO 1085:2007-04