Common examples include ferrovanadium, ferroniobium (ferrocolumbium), ferromolybdenum, ferrotungsten, ferrotitanium, ferrophosphorus, and ferrocalcium silicon. Each is classified here because no dedicated SITC heading exists for it. Importers should verify that the specific alloy is not captured by a more specific provision at the HTS 6- or 10-digit level before defaulting to the NES category.

Because the NES heading covers chemically diverse products, a detailed mill certificate specifying the predominant alloying element, its percentage by weight, and all other significant constituents is essential. Customs may challenge classification if the certificate is ambiguous or if the declared element could place the material under a more specific heading. For novel or uncommon alloys, obtaining a CBP binding ruling in advance is advisable to avoid reclassification and potential duty underpayment issues.