Läpimita

Läpimita is a term used in mechanical engineering and manufacturing to denote the maximum through-path dimension of a part or feature that must pass through another component, opening, or channel. The term—drawn from Finnish elements meaning through and measure—describes a size limit relevant to fit, clearance, and transport. In practice, läpimitta is used during design, procurement, and quality control to ensure parts will pass through required openings and to verify compatibility with manufacturing equipment.

Determination: The läpimitta can be specified as a diameter, width, or other cross-sectional dimension, depending on the orientation of the passage. It is determined from CAD models, engineering drawings, or physical measurement. Common methods include calipers or micrometers for simple geometries, coordinate measuring machines for complex shapes, and optical or laser scanning for assembled components. Tolerances are applied to account for production variation.

Applications: It is used for piping and tubing, fastener assemblies, electrical enclosures, shipping crates, and robotic gripper interfaces, among others. In design, the läpimitta helps confirm clearance in crowded assemblies and ensures parts can traverse manufacturing lines or transit routes. In procurement, specifications include the maximum through-path dimension to avoid incompatibilities.

Limitations and relations: Läpimitta is a static dimension that does not capture dynamic fit, deformation under load, or assembly stresses. It complements other tolerances such as external diameter, inner bore, and envelope. It is related to clearance, fit, minimum bend radius, and envelope dimensions used in tolerance analysis.