7304.51Subheading
Steel, alloy (not stainless steel); seamless, cold-drawn or cold-rolled (cold-reduced), tubes, pipes and hollow profiles of circular cross-section
Section XV — Base metals and articles of base metal
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.