# HS code 8407.31: Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity not exceeding 50 cc

> HS code 8407.31 covers reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity not exceeding 50 cc. It sits in heading 84.07 (spark-ignition reciprocating or rotary internal combustion piston engines) in chapter 84 (nuclear reactors, boilers, machinery and mechanical appliances; parts thereof). Other goods of heading 84.07 are classified under 8407.10 (aircraft engines), 8407.21 (marine propulsion engines, outboard motors), 8407.29 (marine propulsion engines, other), 8407.32 (reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity exceeding 50 cc but not exceeding 250 cc) or 3 others. National tariff lines under 8407.31 are live on border.bot for the United States (2 lines, also used by 1 other country).

Source: https://border.bot/hs-codes/840731
Last updated: 11 October 2026

[HS codes](https://border.bot/hs-codes) / [Chapter 84](https://border.bot/hs-codes/84) / [84.07](https://border.bot/hs-codes/8407) / [8407.31](https://border.bot/hs-codes/840731)

## Key facts

- HS code: 8407.31
- Covers: Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity not exceeding 50 cc
- Heading: [84.07: Spark-ignition reciprocating or rotary internal combustion piston engines](https://border.bot/hs-codes/8407)
- 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 2 lines](https://border.bot/countries/united-states/hs-codes/840731)

## What this code covers

HS code 8407.31 covers reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity not exceeding 50 cc.

The legal text of the subheading is “Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87: Of a cylinder capacity not exceeding 50 cc”, read under “Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87”, in HS2022.

## What it doesn’t cover

Other goods of heading 84.07 are classified under 8407.10 (aircraft engines), 8407.21 (marine propulsion engines, outboard motors), 8407.29 (marine propulsion engines, other), 8407.32 (reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity exceeding 50 cc but not exceeding 250 cc) or 3 others.

- [8407.10](https://border.bot/hs-codes/840710) Aircraft engines
- [8407.21](https://border.bot/hs-codes/840721) Marine propulsion engines: Outboard motors
- [8407.29](https://border.bot/hs-codes/840729) Marine propulsion engines: Other
- [8407.32](https://border.bot/hs-codes/840732) Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87: Of a cylinder capacity exceeding 50 cc but not exceeding 250 cc
- [8407.33](https://border.bot/hs-codes/840733) Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87: Of a cylinder capacity exceeding 250 cm3 but not exceeding 1 000 cm3
- [8407.34](https://border.bot/hs-codes/840734) Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87: Of a cylinder capacity exceeding 1,000 cc
- [8407.90](https://border.bot/hs-codes/840790) Other engines

## How it is structured

8407.31 is a six-digit subheading. Its first two digits, 84, are the chapter; the first four, 8407, are heading 84.07; the last two, 31, 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 84.07: Spark-ignition reciprocating or rotary internal combustion piston engines
- Within the heading: Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87
- Subheading 8407.31: Of a cylinder capacity not exceeding 50 cc

## In other countries

National tariff lines under 8407.31 are live on border.bot for the United States (2 lines, also used by 1 other country).

- [United States](https://border.bot/countries/united-states/hs-codes/840731): 2 lines, used by 1 other country

- Previous subheading: [8407.29](https://border.bot/hs-codes/840729) Marine propulsion engines: Other
- Next subheading: [8407.32](https://border.bot/hs-codes/840732) Reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87: Of a cylinder capacity exceeding 50 cc but not exceeding 250 cc

## Frequently asked questions

### What does HS code 8407.31 cover?

HS code 8407.31 covers reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity not exceeding 50 cc.

### Which heading and chapter is HS code 8407.31 in?

HS code 8407.31 is in heading 84.07 (spark-ignition reciprocating or rotary internal combustion piston engines) in chapter 84 (nuclear reactors, boilers, machinery and mechanical appliances; parts thereof).

### Where are goods of heading 84.07 classified when 8407.31 doesn’t fit?

Other goods of heading 84.07 are classified under 8407.10 (aircraft engines), 8407.21 (marine propulsion engines, outboard motors), 8407.29 (marine propulsion engines, other), 8407.32 (reciprocating piston engines of a kind used for the propulsion of vehicles of Chapter 87, of a cylinder capacity exceeding 50 cc but not exceeding 250 cc) or 3 others.

### Which countries’ tariffs list national lines under HS code 8407.31?

National tariff lines under 8407.31 are live on border.bot for the United States (2 lines, 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/840731.json