Gewindeeinheit

Gewindeeinheit is a term used in mechanical engineering and technical drawing to refer to the unit or set of parameters that describe a screw thread. In many contexts the essential quantities are the nominal diameter and the thread pitch, which together define the basic geometry of the thread. The concept can be found in historical or regional German-language documentation as a compact way to indicate the dimensional information needed to specify a thread, though it is not a fixed, modern SI unit on its own.

In metric thread notation, the thread pitch is the distance between adjacent thread crests, measured in millimeters, and is combined with the nominal diameter (for example, M6 with a pitch of 1.0 mm). In imperial practice, threading is often described by threads per inch (TPI) rather than pitch, which serves a similar role in characterizing the thread geometry. The Gewindeeinheit concept thus encompasses both diameter and pitch/tpi, and may include additional details such as thread angle and tolerance classes in practical specifications.

Today, explicit specification of the individual quantities (d, p or TPI, thread angle, tolerance class) is preferred in standards and drawings, rather than relying on a general term like Gewindeeinheit. The term remains of historical or regional relevance and may appear in older texts, catalogs, or teaching materials.

See also: screw thread, nominal diameter, thread pitch, threads per inch, standard thread types.