Product classification
HS code for Refractory mortar: 3816.00
Refractory cements, mortars, concretes and similar compositions, including dolomite ramming mix, other than products of heading 38.01.
Classification of refractory mortar under HS 3816.00
Refractory mortar is classified under HS code 3816.00, which specifically covers refractory cements, mortars, concretes, and similar compositions. This classification is determined by the material's primary function: its ability to withstand extreme temperatures, typically exceeding 1,500 degrees Celsius, without losing structural integrity or melting. These products are essential in industrial applications where heat resistance is paramount. The classification under Chapter 38 (Miscellaneous chemical products) is appropriate because these mortars are formulated mixtures of non-metallic minerals, such as alumina, silica, or magnesia, often combined with chemical binders. Unlike standard construction mortars, which are classified in Chapter 25 or 32, refractory versions are engineered for thermal stability and chemical resistance against slag and molten metals. The General Interpretative Rules (GIR) dictate that because these are prepared mixtures for refractory use, they must fall under 3816.00, provided they are not based on graphite or other carbon-based materials, which would shift the classification to heading 38.01.
- Covers
- High-alumina refractory mortar used for lining blast furnaces.
- Silica-based mortars designed for glass melting tanks.
- Dolomite ramming mixes used in steelmaking ladles.
- Fireclay mortars for industrial boiler insulation.
- Heat-curable refractory cements for kiln construction.
- Also under 3816.00
- Saint-Gobain Refractories
- RHI Magnesita
- Vesuvius
- Krosaki Harima
- Calderys
Codes often confused with 3816.00
Common mistake. Refractory mortar is frequently misclassified under HS code 2523, which covers Portland cement and other hydraulic cements. However, 2523 is reserved for basic construction materials that lack the specific heat-resistant properties of refractory compositions. Another common error is using HS code 3801.10 for graphite-based refractory materials. While both are used in high-heat environments, 3816.00 specifically excludes products where carbon or graphite is the primary functional component. Additionally, some importers mistakenly use 3214.10 (glaziers' putty and resin cements), but that code is for sealing and surfacing, not for structural refractory applications.
Top exporters and importers of HS 381600 (the code used for refractory mortar), 2025
In 2025, the largest exporter of HS 381600 (the code used for refractory mortar) in UN Comtrade data was China, with 20% of world exports; the largest importer in UN Comtrade data was Indonesia, with 7.7% 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 381600, not only refractory mortar.
Top exporters 2025 · share of world exports
- 1 China $515M 20% of world exports
- 2 Germany $311M 12% of world exports
- 3 United States $228M 8.8% of world exports
World total: $2.6B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Indonesia $225M 7.7% of world imports
- 2 United States $148M 5.1% of world imports
- 3 India $143M 4.9% of world imports
World total: $2.9B 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 refractory mortar
Brazil splits HS 3816.00 into 6 NCM codes. Pick the one that matches your product:
- 3816.00.11Magnesite-based refractory cements and mortars
- 3816.00.12Sillimanite refractory cements and mortars
- 3816.00.19Other refractory cements and mortars
- 3816.00.21Graphite refractory mixes, 50 % or more corundum
- 3816.00.29Other chrome-magnesite, corundum etc. refractories
- 3816.00.90Other refractory concretes and compositions
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about refractory mortar
What is the HS code for Refractory mortar?
The HS code for Refractory mortar is 381600 (Refractory cements, mortars, concretes and similar compositions, including dolomite ramming mix, other than products of heading 38.01). The primary HS code for refractory mortar is 3816.00. This code encompasses all non-carbon based refractory cements and similar compositions used in high-temperature industrial settings.
How do I classify Refractory mortar for customs?
Refractory mortar is classified under HS code 381600 — Refractory cements, mortars, concretes and similar compositions, including dolomite ramming mix, other than products of heading 38.01. This is a 6-digit subheading level code.
Can residential fireplace mortar use this code?
Yes, if the mortar is specifically formulated as a refractory product to withstand high heat, it falls under 3816.00. However, standard masonry mortar used for the exterior of a chimney would likely fall under 3214.90.
Which countries are the top exporters of refractory mortar (HS 381600)?
In 2025, the top exporters of HS 381600 (the code used for refractory mortar) in UN Comtrade data were China ($515M, 20% of world exports), Germany ($311M) and the United States ($228M). World exports came to about $2.6B, 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 refractory mortar (HS 381600)?
In 2025, the top importers of HS 381600 (the code used for refractory mortar) in UN Comtrade data were Indonesia ($225M, 7.7% of world imports), the United States ($148M) and India ($143M). World imports came to about $2.9B, 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 Refractory mortar the same in all countries?
The base HS code 381600 for Refractory mortar 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 refractory mortar in Brazil?
Brazil splits HS 381600 into 6 NCM codes, so the right one for refractory mortar depends on the product's details: 3816.00.11 (Magnesite-based refractory cements and mortars), 3816.00.12 (Sillimanite refractory cements and mortars), 3816.00.19 (Other refractory cements and mortars), 3816.00.21 (Graphite refractory mixes, 50 % or more corundum), 3816.00.29 (Other chrome-magnesite, corundum etc. refractories), 3816.00.90 (Other refractory concretes and compositions).