Product classification
HS code for Machine screws: 7318.15
Iron or steel, threaded screws and bolts n.e.c. in item no. 7318.1, whether or not with their nuts or washers.
Classification of machine screws under HS 7318.15
Machine screws are classified under HS code 7318.15. This code falls within Chapter 73, which covers articles of iron or steel. Specifically, heading 7318 encompasses screws, bolts, nuts, coach screws, screw hooks, rivets, cotters, cotter-pins, washers, and similar articles. Machine screws are defined by their threaded shank, designed to be fastened into a tapped hole or used with a nut. Classification under 7318.15 is driven by the fact that these are threaded articles of iron or steel that are not coach screws or wood screws. The distinction is critical because machine screws have a finer, more precise thread compared to self-tapping or wood screws. According to Section XV Note 2, these are considered 'parts of general use,' meaning they are classified here regardless of the final machine they are intended for. Whether the screw is made of stainless steel, carbon steel, or alloy steel, as long as it is an iron/steel threaded fastener of this type, 7318.15 is the appropriate designation.
- Covers
- Pan head machine screws
- Flat head machine screws
- Hex drive machine screws
- Socket head cap screws
- Stainless steel machine bolts
- Threaded fasteners for precision machinery
- Also under 7318.15
- Fastenal hex bolts
- Würth machine screws
- Böllhoff self-tapping screws
- ITW Buildex anchor bolts
Codes often confused with 7318.15
Common mistake. A frequent point of confusion occurs between 7318.15 and 7318.14. HS code 7318.14 is specifically for self-tapping screws. While they look similar, self-tapping screws create their own threads in the material, whereas machine screws require a pre-formed internal thread. Additionally, 7318.12 (wood screws) is often used incorrectly for machine screws used in composite materials. It is also important to avoid 7318.16, which is reserved for nuts; while screws and nuts are often sold together, they must be classified separately unless they are presented as a single assembly in specific kits.
Top exporters and importers of HS 731815 (the code used for machine screws), 2025
In 2025, the largest exporter of HS 731815 (the code used for machine screws) in UN Comtrade data was China, with 20% of world exports; the largest importer in UN Comtrade data was the United States, with 13% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 731815, not only machine screws.
Top exporters 2025 · share of world exports
- 1 China $4.5B 20% of world exports
- 2 Germany $3.2B 14% of world exports
- 3 United States $2.5B 11% of world exports
World total: $22.7B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $2.8B 13% of world imports
- 2 Germany $2.2B 9.8% of world imports
- 3 Mexico $1.5B 6.7% of world imports
World total: $22.3B 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 code for machine screws
Brazil classifies machine screws under NCM 7318.15.00: HS 7318.15 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
EU Regulatory Requirements
This product falls under the Carbon Border Adjustment Mechanism (CBAM). Importers to the EU must declare embedded carbon emissions and purchase CBAM certificates.
Questions about machine screws
What is the HS code for Machine screws?
The HS code for Machine screws is 731815 (Iron or steel; threaded screws and bolts n.e.c. in item no. 7318.1, whether or not with their nuts or washers). The HS code for machine screws made of iron or steel is 7318.15.
How do I classify Machine screws for customs?
Machine screws is classified under HS code 731815 — Iron or steel; threaded screws and bolts n.e.c. in item no. 7318.1, whether or not with their nuts or washers. This is a 6-digit subheading level code.
Does the HS code change if the screw is made of stainless steel?
No, 7318.15 covers threaded screws and bolts of iron or steel, which includes stainless steel variants, though specific national tariff lines may further subdivide by material type.
Which countries are the top exporters of machine screws (HS 731815)?
In 2025, the top exporters of HS 731815 (the code used for machine screws) in UN Comtrade data were China ($4.5B, 20% of world exports), Germany ($3.2B) and the United States ($2.5B). World exports came to about $22.7B, 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 machine screws (HS 731815)?
In 2025, the top importers of HS 731815 (the code used for machine screws) in UN Comtrade data were the United States ($2.8B, 13% of world imports), Germany ($2.2B) and Mexico ($1.5B). World imports came to about $22.3B, 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.
Is the HS code for Machine screws the same in all countries?
The base HS code 731815 for Machine screws is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for machine screws in Brazil?
In Brazil, machine screws (HS 731815) is classified under NCM 7318.15.00.