HS code · 6-digit subheading
HS Code 8455.21 – Metal-rolling mills; hot or combination hot and cold rolling mills
HS code 8455.21 is the 6-digit subheading for metal-rolling mills, hot or combination hot and cold rolling mills. It is used for hot strip mills, plate mills, bloom mills, billet mills and reversing hot mills.
What HS 8455.21 covers
This specific HS code focuses on metal-rolling mills designed for hot rolling or a combination of hot and cold rolling processes. Hot rolling involves processing metal at high temperatures, above its recrystallization point, to achieve significant deformation and reduce thickness, while combination mills offer the flexibility for both hot and subsequent cold processes. These mills are central to the primary shaping of steel and other metals into semi-finished products like slabs, blooms, and billets, as well as finished products like plates and strips. Importers are typically large integrated steelworks and major metal processing companies worldwide, investing heavily to meet global demand for basic metal products. Exporters are specialized heavy machinery manufacturers with advanced engineering capabilities. The trade in these massive, high-investment machines is a key indicator of global industrial capacity and demand for foundational metal products.
- Covers
- Hot strip mills
- Plate mills
- Bloom mills
- Billet mills
- Reversing hot mills
- Tandem hot mills
- Combination hot and cold mills
- Universal rolling mills
- Examples
- SMS Group hot strip mill
- Danieli plate mill
- Primetals Technologies hot rolling mill
- Fives reversing hot mill
Codes often confused with 8455.21
Common mistake. This is a sub-category of 845510, specifically for hot or combination hot/cold mills. It should not be confused with purely cold rolling mills (845522) or other metal-forming machinery that doesn't involve rolling.
Top exporters and importers of HS code 845521, 2025
In 2025, the largest exporter of HS code 845521 in UN Comtrade data was China, with 49% of world exports; the largest importer in UN Comtrade data was Mexico, with 22% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 China $269M 49% of world exports
- 2 Germany $105M 19% of world exports
- 3 Italy $98M 18% of world exports
World total: $553M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Mexico $193M 22% of world imports
- 2 India $142M 16% of world imports
- 3 Brazil $121M 14% of world imports
World total: $881M Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM codes for 8455.21 2
Brazil splits HS 8455.21 into 2 NCM codes, Mercosur's 8-digit tariff lines.
- 8455.21.10 Hot or hot-and-cold rolling mills, plain rollsDe cilindros lisos
- 8455.21.90 Other hot or hot-and-cold rolling millsOutros
All Brazil NCM codes in heading 84.55 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 8455.21
What is HS code 845521?
HS code 845521 is a 6-digit subheading in the Harmonized System that covers: Metal-rolling mills; hot or combination hot and cold rolling mills. This specific HS code focuses on metal-rolling mills designed for hot rolling or a combination of hot and cold rolling processes. Hot rolling involves processing metal at high temperatures, above its recrystallization point, to achieve significant deformation and reduce thickness, while combination mills offer the flexibility for both hot and subsequent cold processes. These mills are central to the primary shaping of steel and other metals into semi-finished products like slabs, blooms, and billets, as well as finished products like plates and strips. Importers are typically large integrated steelworks and major metal processing companies worldwide, investing heavily to meet global demand for basic metal products. Exporters are specialized heavy machinery manufacturers with advanced engineering capabilities. The trade in these massive, high-investment machines is a key indicator of global industrial capacity and demand for foundational metal products.
What products fall under HS code 845521?
Hot strip mills, Plate mills, Bloom mills, Billet mills, Reversing hot mills, Tandem hot mills, Combination hot and cold mills, Universal rolling mills
What are common misclassifications for HS code 845521?
This is a sub-category of 845510, specifically for hot or combination hot/cold mills. It should not be confused with purely cold rolling mills (845522) or other metal-forming machinery that doesn't involve rolling.
Which countries are the top exporters of goods under HS code 845521?
In 2025, the top exporters of HS code 845521 in UN Comtrade data were China ($269M, 49% of world exports), Germany ($105M) and Italy ($98M). World exports came to about $553M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of goods under HS code 845521?
In 2025, the top importers of HS code 845521 in UN Comtrade data were Mexico ($193M, 22% of world imports), India ($142M) and Brazil ($121M). World imports came to about $881M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
How is HS code 845521 structured?
HS code 845521 is a 6-digit subheading under the Harmonized System. The first 2 digits (84) identify the chapter, digits 3-4 (55) identify the heading, and digits 5-6 (21) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 845521?
Brazil splits HS code 845521 into 2 NCM codes: 8455.21.10 (Hot or hot-and-cold rolling mills, plain rolls), 8455.21.90 (Other hot or hot-and-cold rolling mills). The first 6 digits of each match the HS code.