# HS code 8455.21: Other rolling mills, hot or combination hot and cold

> HS code 8455.21 covers other rolling mills, hot or combination hot and cold. It sits in heading 84.55 (metal-rolling mills and rolls therefor) in chapter 84 (nuclear reactors, boilers, machinery and mechanical appliances; parts thereof). Other goods of heading 84.55 are classified under 8455.10 (tube mills), 8455.22 (other rolling mills, cold), 8455.30 (rolls for rolling mills) or 8455.90 (other parts). National tariff lines under 8455.21 are live on border.bot for the United States (1 line, also used by 1 other country).

Source: https://border.bot/hs-codes/845521
Last updated: 11 October 2026

[HS codes](https://border.bot/hs-codes) / [Chapter 84](https://border.bot/hs-codes/84) / [84.55](https://border.bot/hs-codes/8455) / [8455.21](https://border.bot/hs-codes/845521)

## Key facts

- HS code: 8455.21
- Covers: Other rolling mills, hot or combination hot and cold
- Heading: [84.55: Metal-rolling mills and rolls therefor](https://border.bot/hs-codes/8455)
- Chapter: [84: Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof](https://border.bot/hs-codes/84)
- Edition: HS2022
- Duty in the United States: [See its 1 line](https://border.bot/countries/united-states/hs-codes/845521)

## What this code covers

HS code 8455.21 covers other rolling mills, hot or combination hot and cold.

The legal text of the subheading is “Other rolling mills: Hot or combination hot and cold”, read under “Other rolling mills”, in HS2022.

## What it doesn’t cover

Other goods of heading 84.55 are classified under 8455.10 (tube mills), 8455.22 (other rolling mills, cold), 8455.30 (rolls for rolling mills) or 8455.90 (other parts).

- [8455.10](https://border.bot/hs-codes/845510) Tube mills
- [8455.22](https://border.bot/hs-codes/845522) Other rolling mills: Cold
- [8455.30](https://border.bot/hs-codes/845530) Rolls for rolling mills
- [8455.90](https://border.bot/hs-codes/845590) Other parts

## How it is structured

8455.21 is a six-digit subheading. Its first two digits, 84, are the chapter; the first four, 8455, are heading 84.55; the last two, 21, identify the subheading within the heading.

Countries add their own digits after these six for their national tariff lines.

- Chapter 84: Nuclear reactors, boilers, machinery and mechanical appliances; parts thereof
- Heading 84.55: Metal-rolling mills and rolls therefor
- Within the heading: Other rolling mills
- Subheading 8455.21: Hot or combination hot and cold

## In other countries

National tariff lines under 8455.21 are live on border.bot for the United States (1 line, also used by 1 other country).

- [United States](https://border.bot/countries/united-states/hs-codes/845521): 1 line, used by 1 other country

- Previous subheading: [8455.10](https://border.bot/hs-codes/845510) Tube mills
- Next subheading: [8455.22](https://border.bot/hs-codes/845522) Other rolling mills: Cold

## Frequently asked questions

### What does HS code 8455.21 cover?

HS code 8455.21 covers other rolling mills, hot or combination hot and cold.

### Which heading and chapter is HS code 8455.21 in?

HS code 8455.21 is in heading 84.55 (metal-rolling mills and rolls therefor) in chapter 84 (nuclear reactors, boilers, machinery and mechanical appliances; parts thereof).

### Where are goods of heading 84.55 classified when 8455.21 doesn’t fit?

Other goods of heading 84.55 are classified under 8455.10 (tube mills), 8455.22 (other rolling mills, cold), 8455.30 (rolls for rolling mills) or 8455.90 (other parts).

### Which countries’ tariffs list national lines under HS code 8455.21?

National tariff lines under 8455.21 are live on border.bot for the United States (1 line, also used by 1 other country).

## Sources and updates

The Harmonized System legal text comes from border.bot release 2 (edition HS 2022), imported from a file, and has been live since 11 October 2026.

This page was last updated on 11 October 2026.

Guidance from published tariff data, not a binding ruling. For a decision customs must follow, apply to the destination’s customs authority for a binding tariff ruling.

Machine-readable: https://border.bot/hs-codes/845521.json