2518.20Subheading
Dolomite, calcined or sintered; including dolomite roughly trimmed, or merely cut by sawing or otherwise into blocks or slabs of rectangular (including square) shape
Section V — Mineral products
This is a 6-digit subheading — the most specific level of the international HS. Country tariff schedules extend it further; the US tariff lines (HTS) below refine it to 8–10 digits for duty purposes.
US tariff lines for this subheading are not in the bundled starter dataset yet — the full HTS schedule is coming soon. You can still search by code in the tariff simulator.