Randmaß

Randmaß is a German term used in engineering, manufacturing, and design to denote an edge margin or permitted deviation from nominal dimensions. It refers to the amount of extra material or space at the edge of a part that accommodates manufacturing processes, finishing, and assembly. Randmaß is closely related to, but distinct from, general tolerances: while tolerance can apply to any dimension, Randmaß specifically concerns the edge region and the clearance or overhang at the edge.

In technical drawings, Randmaß is stated as a permissible deviation around the nominal size. For example, a nominal length (Nennmaß) of 50 mm with a Randmaß of ±0.2 mm allows an actual length between 49.8 and 50.2 mm. The concept is used across industries such as metalworking, machining, and woodworking to ensure parts fit, reduce burrs, and accommodate coatings or finishing processes. Randmaß plays a role in ensuring consistent assembly and interchangeability of components.

Relation to other terms: Randmaß is part of the broader field of dimensional tolerancing and is governed by standards that define how tolerances are stated on drawings, such as DIN or ISO standards. The exact value of Randmaß depends on the part’s function, material, manufacturing process, and quality requirements. It is typically specified by engineers or designers in the manufacturing documentation.

Etymology: Randmaß combines Rand (edge) and Maß (measure). In printing or graphic contexts, margins or bleed areas may be referred to with related concepts, but Randmaß is primarily a technical term in dimensional tolerancing.