Maßlinien

Maßlinien are dimension lines used in technical drawings to convey measurements. They form a key part of the bemaßung (dimensioning) system and indicate the size, shape, or location of features on an object. A typical dimension line includes the line itself, arrowheads at both ends, and the numeric value with units.

The dimension line is usually drawn parallel to the measured feature or at a convenient orientation, and it is offset from the feature by extension lines. The extension lines connect the feature’s relevant points to the dimension line, establishing exactly which distances are being specified. The overall composition aims for clarity and to avoid intersecting other lines or text.

Common types of dimensions include linear (length, width, height), angular (the angle between two lines or faces), and radial or diameter dimensions (r or Ø for circles and arcs). Dimensions can be placed outside the object or, in some cases, inside enclosed features, depending on space and readability. Tolerances may be indicated separately in the same area or via a separate feature control frame.

Standards govern the use of Maßlinien, ensuring consistency across drawings. In practice, dimensioning follows international and national norms, such as ISO 129 and related DIN ISO standards, with regional adaptations (for example, ASME Y14.5 in the United States). Adherence to conventions—clear placement, avoiding redundant or ambiguous dimensions, and consistent units—facilitates accurate manufacturing, inspection, and communication among engineers and fabricators.