The location of the serial number on a Naumann machine varies depending on its age and whether it is a hand-crank, treadle, or early electric model.
| Feature | Indicates | | :--- | :--- | | | 1880–1895 | | Hand-crank only (no belt wheel) | 1870–1890 | | Boat-shaped shuttle (long bullet) | 1870–1885 | | Flat metal finger guard over the needle | 1890–1905 | | Reverse lever (stitch back button) | Post-1895 | | “Germany” stamped on the arm | Post-1891 (McKinley Tariff Act) | | Decorated silver plate on the arm | 1880–1900 | | Black plastic (Bakelite) hand wheel | 1920–1940 | naumann sewing machine serial number