Operations such as pickling (acid descaling), oiling, shot blasting, or temper-rolling that go beyond simple hot-rolling but stop short of cold-reduction or surface coating can constitute 'further working.' The classification boundary is fact-specific, and importers should obtain a binding ruling from CBP if the processing steps are ambiguous, as misclassification can trigger both duty underpayment and trade-remedy exposure.

The NES designation means this heading applies only when the product does not fit a more specific further-worked or coated heading. Importers must first rule out all more specific classifications — including coated, plated, clad, and cold-rolled headings — before using this residual category. Using an NES heading when a more specific one applies is a common classification error that can be identified during a CBP audit.