Analysis
HTS 2810.00.00 covers oxides of boron; boric acids under heading 2810 (oxides of boron; boric acids).
The general duty rate is 1.5% of the customs value, which is in the middle of the rates in chapter 28 (37th percentile of 274 lines with an ad valorem rate). On a shipment valued at $10,000 that is $150 in duty before any Chapter 99 additions or preference claims.
It is the only US line under subheading 2810.00, so the six-digit code used by every Harmonized System country and the eight-digit US line describe the same goods; a foreign tariff or an exporter's invoice showing 2810.00 points straight here.
Goods that qualify under GSP, the Australia FTA, the Bahrain FTA, the Chile FTA, the Colombia TPA, and 12 others can enter duty-free instead of paying 1.5%. It is also eligible under GSP, the developing-country programme, which Congress has to renew; check whether GSP is in force on the entry date.
Census statistics map these goods to NAICS 325180 (Other Basic Inorganic Chemical Manufacturing), an industry of 705 US establishments employing 41,447 people. That concordance is how imports of this line are compared with US output.