A retrofit that adds servo-driven, programmable axis control converts the machine to numerically controlled status, which would move it to SITC 73151. If the retrofit provides only digital readout without servo-driven positioning, the machine remains non-CNC and stays in 73152. The functional capability of the control system — not the original machine design — determines classification after a retrofit.

Used industrial machinery generally follows the same tariff classification as new equipment, but CBP may scrutinize the declared value more closely for used machines. Some states and localities also have environmental or safety regulations governing used machinery imports. There are no federal admissibility restrictions specific to used metalworking machines, but importers should ensure accurate valuation and condition disclosure in entry documentation.