Refractory cements — HTS 3816
Refractory cements, mortars, concretes and similar compositions, including dolomite ramming mix, other than products of heading 3801
Chapter 38 › Heading 3816
2026 HTS Rev 19 Synced Rules verified Operational
Written to help non-specialists understand this page. Rates, dates, and legal facts come from the official records above and on the linked source.
HTS heading 3816 groups together prepared refractory materials: heat-resistant cements, mortars, concretes, and similar compositions used to line, repair, fill, or construct furnaces, kilns, reactors, and other high-temperature equipment. It also includes dolomite ramming mix. The heading excludes products classified in heading 3801, so the product’s composition and intended use must be reviewed before relying on heading 3816.
Heading 3816 is only a 4-digit category, not the final import classification. To reach the correct 8-digit HTSUS code, start with the product’s formulation and physical form, then follow the available subheadings and statistical suffixes. The deciding description may distinguish materials or types, such as whether the product is a cement, mortar, concrete, ramming mix, or another prepared refractory composition. Use the HTSUS notes and the complete product description rather than choosing based only on a brand name or marketing term.
What to check
- Obtain the manufacturer’s full ingredient list, technical data sheet, and safety data sheet; identify the principal refractory material and any binder.
- Confirm the product’s physical form and intended application, such as castable concrete, mortar, repair cement, or ramming mix.
- Read the heading, subheading, legal notes, and relevant exclusions together; check whether heading 3801 or another heading better describes the composition.
- Compare the product’s technical description with the wording of each 8-digit option, including any material or type distinctions and statistical suffixes.
- Document the classification reasoning and seek a customs broker or binding ruling when the formulation, use, or heading choice is ambiguous.
HTS heading 3816 summary
Refractory cements is a 4-digit product category containing 2 published product-code lines in this snapshot. A heading does not carry one universal duty rate; classification must be narrowed to the line matching the product facts.
How to find your code in this category
A heading is a product category. To get the exact duty, narrow from this 4-digit heading to a sub-category (usually by material), then open the 8-digit code that matches your product.
Open any code in the tables below to see its exact duty rate, a duty calculator (enter your shipment value → estimated duty and landed cost), the rate-change history chart, and the country-by-country breakdown (including Section 301/232 add-on duties).
Why you have to click in: a single category can contain products with very different duties. The rate depends on the specific product — its material and construction — and on the country of origin, and those only get pinned down at the 8-digit code level. That is why this page points you to codes instead of showing one rate for the whole category.
Product codes & duty rates
👇 Each row is a specific product code — click a blue code to open its full page with exact duty rates by country, the rate-history chart, and a duty calculator. 👉
| Code | Description | General (MFN) | Special | Column 2 |
|---|---|---|---|---|
| 3816.00.10.00 👉 | Dolomite ramming mix | Free | — | 30% |
| 3816.00.20 👉 | Other | 3% | Free | 30% |
"Special" shows the free-trade-agreement rate; open a code to see exactly which countries qualify.
Common questions
What products fall under HTS heading 3816?
Refractory cements, mortars, concretes and similar compositions, including dolomite ramming mix, other than products of heading 3801. To classify a specific item you must pick the matching sub-category and 8-digit code above; the right choice usually depends on the material and construction of the product.
How do I choose the right code within this category?
Start from the sub-categories (typically divided by material—for example cotton versus man-made fibers), then open the active 8- or 10-digit code that matches the product. When unsure, a licensed customs broker or a CBP binding ruling can confirm the classification.
Reference information only, not customs, legal, or classification advice. Confirm the current code and rate against the official HTS before you import.