External Dimension

External Dimension is a technical term commonly used in foreign trade and manufacturing, specifically referring to the diameter measurement of the outer contour of circular or cylindrical products (such as pipes, bearings, flanges, sealing rings, etc.), usually expressed in millimeters (mm) or inches. In foreign trade contracts, external dimension is one of the core parameters of specification clauses, directly affecting product assembly, compatibility, and performance. Usage scenarios include: product specifications, purchase orders, quality inspection reports, packing lists, and goods descriptions in letters of credit. Notes: 1) The measurement position (e.g., pipe end outer diameter, maximum outer diameter) and tolerance range (e.g., ±0.5mm) must be clearly specified to avoid disputes arising from different measurement references; 2) It must be strictly distinguished from 'Inner Dimension,' which refers to the internal bore diameter; 3) For non-circular products, external dimension is not applicable; instead, 'Overall Dimension' or 'External Size' should be used. In addition, different countries may adopt different standards (such as ISO, DIN, ASTM), and standard consistency must be confirmed before quotation and signing to prevent non-conforming delivery.