A boring-milling machine that performs boring and milling but lacks automatic tool change from a magazine or similar device is classified here under 845931 or 845939. Once a machine adds automatic tool-change capability from a magazine and can perform multiple machining types, it crosses into the machining-centers heading. The chapter notes define machining centers, and that definition is the controlling reference.

Yes. Knee-type milling machines — where the worktable is mounted on a vertically adjustable knee — are classified under 845951 (NC) or 845959 (non-NC). Non-knee-type milling machines, including bed-type and ram-type mills, fall under 845961 (NC) or 845969 (non-NC). The physical construction of the table-support mechanism determines which subheading applies.