DINReihen

DINReihen is a German-language term used to refer to families or groups of standards issued by the Deutsches Institut für Normung (DIN) that are organized into series. The term is not a single formal standard but a way to describe how DIN issues standards grouped by a common prefix or theme, such as a lettered series.

The most well-known example is the A-Reihe, which designates the standard paper sizes from A0 upward (A0, A1, A2, A3, A4, etc.). These sizes share a constant aspect ratio of 1 to the square root of 2, a convention that originated in DIN 476 and later became ISO 216. Related series include the B-Reihe and the C-Reihe. The B-Reihe covers additional sizes used for posters and intermediate formats, while the C-Reihe is designed for envelopes that accommodate the corresponding A-series sheets.

Beyond paper sizes, DINReihen can refer to other groups of standards identified by a common series designation within DIN’s catalog, such as tolerance classes, component specifications, or product standards. Individual documents within a DIN-Reihe are cited by their full DIN number (for example, DIN 476, DIN 12345), rather than by a generic “Reihe” name.

In modern practice, many DIN standards are harmonized with ISO or EN designations (for example, DIN EN ISO 216). The informal use of “DIN-Reihe” persists in German technical literature to signal that a given standard belongs to a broader series, but practitioners typically reference the exact standard number for precise requirements.