‘Numerical control’ units for machine tools and ‘numerically controlled’ machine tools, other than those specified in the CML or in Regulation (EU) 2021/821 (see List of Items Controlled): a. ‘Numerical control’ units for machine tools: 1. Having four interpolating axes that can be coordinated simultaneously for contouring control; or 2. Having two or more axes that can be coordinated simultaneously for contouring control and a minimum programmable increment better (less) than 0,001 mm; 3. ‘Numerical control’ units for machine tools having two, three or four interpolating axes that can be coordinated simultaneously for contouring control, and capable of receiving directly (on-line) and processing computer-aided-design (CAD) data for internal preparation of machine instructions; or b. Motion control boards specially designed for machine tools and having any of the following characteristics: 1. Interpolation in more than four axes; 2. Capable of real-time processing of data to modify tool path, feed rate and spindle data, during the machining operation, by any of the following: a. Automatic calculation and modification of part program data for machining in two or more axes by means of measuring cycles and access to source data; or b. Adaptive control with more than one physical variable measured and processed by means of a computing model (strategy) to change one or more machining instructions to optimize the process; or 3. Capable of receiving and processing CAD data for internal preparation of machine instructions; c. ‘Numerically controlled’ machine tools that, according to the manufacturer’s technical specifications, can be equipped with electronic devices for simultaneous contouring control in two or more axes and that have both of the following characteristics: 1. Two or more axes that can be coordinated simultaneously for contouring control; and 2. Positioning accuracies according to ISO 230/2 (2006), with all compensations available: a. Better than 15 μm along any linear axis (overall positioning) for grinding machines; b. Better than 15 μm along any linear axis (overall positioning) for milling machines; or c. Better than 15 μm along any linear axis (overall positioning) for turning machines; or d. Machine tools, as follows, for removing or cutting metals, ceramics or ‘composites’, that, according to the manufacturer’s technical specifications, can be equipped with electronic devices for simultaneous contouring control in two or more axes: 1. Machine tools for turning, grinding, milling or any combination thereof, having two or more axes that can be coordinated simultaneously for contouring control and having any of the following characteristics: a. One or more contouring ‘tilting spindles’; Note: this applies to machine tools for grinding or milling only. b. ‘Camming’ (axial displacement) in one revolution of the spindle less (better) than 0,0006 mm total indicator reading (TIR); Note: this applies to machine tools for turning only. c. ‘Run-out’ (out-of-true running) in one revolution of the spindle less (better) than 0,0006 mm total indicator reading (TIR); or d. The positioning accuracies, with all compensations available, are less (better) than: 0,001 o on any rotary axis; 2. Electrical discharge machines (EDM) of the wire feed type that have five or more axes that can be coordinated simultaneously for contouring control.