An automatic drafting machine in this heading is designed to guide drawing instruments (pens, scribers) along a mechanical or electronically controlled arm to produce technical drawings, with the human operator directing the design process. A computer-controlled plotter, by contrast, receives digital files and reproduces them autonomously and is typically classified as a printing or output device. The presence of a drafting arm, coordinate measuring function, or manual override capability supports classification here.

While volumes are modest, non-electronic calculating instruments including slide rules and planimeters continue to be imported for specialized engineering, educational, and collector markets. Classification here is straightforward for purely mechanical instruments. Importers should note that even low-value shipments require correct HTS classification, and country-of-origin marking requirements apply regardless of unit value.