Nennmaß

Nennmaß is a German term that translates to "nominal size" or "nominal dimension" in English. It refers to the theoretical or intended size of a part, component, or measurement. In engineering, manufacturing, and construction, nennmaß is the specified size that is used for design, planning, and documentation purposes. It is the ideal size that a part should have if it were manufactured perfectly.

In practice, manufactured items rarely achieve their nennmaß exactly due to variations in the manufacturing process, material properties, and environmental factors. Therefore, nennmaß is always associated with tolerances, which define the permissible range of deviation from the nominal size. The actual measured size of a part is known as the Istmaß, or actual size. The difference between the nennmaß and the Istmaß is the Abmaß, or deviation.

Understanding nennmaß is crucial for ensuring interchangeability and proper function of parts. For example, when ordering bolts and nuts, the nennmaß of the bolt, such as M10, indicates its nominal diameter and thread pitch. The actual bolt and nut will have tolerances that ensure they fit together correctly within specified limits. In construction, nennmaß for lumber might be a standard dimension that is then planed down, resulting in a slightly smaller actual size. Nennmaß serves as the reference point for all quality control and inspection processes.