Generally, slitting a wide electrical steel coil to under 600 mm produces a product that shifts from the wide-strip heading (67511) to the narrow-strip heading (67512). The classification follows the physical dimensions of the product as imported, not the dimensions of the original master coil. Importers should ensure invoices and packing lists reflect the actual slit width to support correct classification.

Key specifications include core loss (watts per kilogram at a given flux density and frequency), permeability, coating type (typically an insulating coating to reduce eddy currents between laminations), thickness tolerance, and slit-width tolerance. For grain-oriented grades, the rolling direction relative to the slit width also matters. These parameters should be confirmed against the end-use motor design requirements and verified on mill test certificates.