6903.10
Containing by weight more than 50 percent of free carbon
Other refractory ceramic goods (for example, retorts, crucibles, muffles, nozzles, plugs, supports, cupels, tubes, pipes, sheaths, rods and slide gates), other than those of siliceous fossil meals or of similar siliceous earths
Where this code sits
- Section XIII · Chapter69 — CERAMIC PRODUCTSARTICLES OF STONE, PLASTER, CEMENT, ASBESTOS, MICA OR SIMILAR MATERIALS; CERAMIC PRODUCTS; GLASS AND GLASSWARE
- Heading6903 — Other refractory ceramic goods (for example, retorts, crucibles, muffles, nozzles, plugs, supports, cupels, tubes, pipes, sheaths, rods and slide gates), other than those of siliceous fossil meals or of similar siliceous earths
- Subheading6903.10 — Containing by weight more than 50 percent of free carbon
Six digits is as far as the international nomenclature goes, and it is the same six digits in every country that applies the Harmonized System. Your destination adds further digits of its own, and the rate lives on that national line — which is why the US lines below run to eight and ten digits, and why the lookups go to each authority's own tariff.
Duty rate
USITC Harmonized Tariff Schedule of the United States, Revision 18 (2026) · retrieved 13/09/2026
Measures in force on top of this rate
- Antidumping/countervailing duties not checked — they are administered separately, keyed to the exporter, and can exceed the tariff rate. Check for an order in force before relying on this total.
Paste 6903.10 into the lookup and follow it down to your national line.
US national lines under 6903.10
The United States subdivides this subheading into 1 line. They share a duty rate, so the classification below the subheading affects reporting rather than the amount.
| Line | Description | General | Preferential |
|---|---|---|---|
| 6903.10.00.00 | Containing by weight more than 50 percent of free carbon | Free | — |
A blank General cell means the line states no rate of its own and takes the one above it — the line it is stated on is named, so the figure can be checked where it actually appears. Preferential rates are listed with the programme codes that grant them; the schedule offering a rate is not the same as your goods qualifying for it.
Preferential rates for 6903.10
No preference programme applies to these lines for any origin — the general rate is the rate, wherever the goods come from. That is worth knowing: there is nothing to claim here, so no certificate of origin will reduce the duty.
What chapter 69 excludes
A subheading's wording does not decide a classification — the legal notes do. These are the notes that push goods out of this chapter even when the description seems to fit.
2. This chapter does not cover:
- (a) Products of heading 2844;
- (b) Articles of heading 6804;
- (c) Articles of chapter 71 (for example, imitation jewelry);
- (d) Cermets of heading 8113;
- (e) Articles of chapter 82;
- (f) Electrical insulators (heading 8546) or fittings of insulating material (heading 8547);
- (g) Artificial teeth (heading 9021);
- (h) Articles of chapter 91 (for example, clocks and clock cases);
- (ij) Articles of chapter 94 (for example, furniture, luminaires and lighting fittings, prefabricated buildings);
- (k) Articles of chapter 95 (for example, toys, games and sports equipment);
- (l) Articles of heading 9606 (for example, buttons) or of heading 9614 (for example, smoking pipes); or
- (m) Articles of chapter 97 (for example, works of art).
3. For the purposes of headings 6905 and 6907, the term "tiles" does not include any article 3.2 cm or more in thickness.
Legal notes that govern this code
Reproduced from the published tariff schedule. Section and chapter notes are binding and are part of the nomenclature itself; statistical notes are US reporting rules and are not classification law.
Chapter 69 — Notes
Legal Notes of the Harmonized System. Binding, and part of the international nomenclature.
1. This chapter applies only to ceramic products which have been fired after shaping:
(a) Headings 6904 to 6914 apply only to such products other than those classifiable in headings 6901 to 6903;
(b) Articles heated to temperatures less than 800 °C for purposes such as curing of resins, accelerating hydration reactions, or for the removal of water or other volatile components, are not considered to be fired. Such articles are excluded from Chapter 69; and
(c) Ceramic articles are obtained by firing inorganic, nonmetallic materials which have been prepared and shaped previously at, in general, room temperature. Raw materials comprise, inter alia, clays, siliceous materials including fused silica, materials with a high melting point, such as oxides, carbides, nitrides, graphite or other carbon, and in some cases binders such as refractory clays or phosphates.
2. This chapter does not cover:
(a) Products of heading 2844;
(b) Articles of heading 6804;
(c) Articles of chapter 71 (for example, imitation jewelry);
(d) Cermets of heading 8113;
(e) Articles of chapter 82;
(f) Electrical insulators (heading 8546) or fittings of insulating material (heading 8547);
(g) Artificial teeth (heading 9021);
(h) Articles of chapter 91 (for example, clocks and clock cases);
(ij) Articles of chapter 94 (for example, furniture, luminaires and lighting fittings, prefabricated buildings);
(k) Articles of chapter 95 (for example, toys, games and sports equipment);
(l) Articles of heading 9606 (for example, buttons) or of heading 9614 (for example, smoking pipes); or
(m) Articles of chapter 97 (for example, works of art).
Chapter 69 — Additional U.S. Notes
Additional U.S. Notes. Binding in the United States; not part of the international HS.
1. For the purposes of headings 6902 and 6903, the term "refractory" is applied to articles which have a pyrometric cone equivalent of at least 1500°C when heated at 60°C per hour (pyrometric cone 18). Refractory articles have special properties of strength and resistance to thermal shock and may also have, depending upon the particular uses for which designed, other special properties such as resistance to abrasion and corrosion.
2. For the purposes of heading 6902, a brick which contains both chromium and magnesium is classifiable according to which of those components (expressed as Cr 2O 3 or MgO, respectively) is the greater by weight.
3. For the purposes of headings 6905 and 6907, the term "tiles" does not include any article 3.2 cm or more in thickness.
5. For the purposes of headings 6909 through 6914:
(a) The terms "porcelain,""china" and"chinaware"embrace ceramic ware (other than stoneware), whether or not glazed or decorated, having a fired white body (unless artificially colored) which will not absorb more than 0.5 percent of its weight of water and is translucent in thicknesses of several millimeters. The term"stoneware" as used in this note, embraces ceramic ware which contains clay as an essential ingredient, is not commonly white, will absorb not more than 3 percent of its weight of water, and is naturally opaque (except in very thin pieces) even when absorption is less than 0.1 percent.
(b) The term "bone chinaware" embraces chinaware or porcelain the body of which contains 25 percent or more of calcined bone or tricalcium phosphate.
(c) The term "earthenware" embraces ceramic ware, whether or not glazed or decorated, having a fired body which contains clay as an essential ingredient, and will absorb more than 3 percent of its weight of water.
(d) The water absorption of a ceramic body shall be determined by ASTM test method designated C373 (except that test specimens may have a minimum weight of 10 g, and may have one large surface glazed).
6. For the purposes of headings 6911 and 6912:
(a) The term "available in specified sets" embraces plates, cups, saucers and other articles principally used for preparing, serving or storing food or beverages, or food or beverage ingredients, which are sold or offered for sale in the same pattern, but no article is classifiable as being "available in specified sets" unless it is of a pattern in which at least the articles listed below in (b) of this note are sold or offered for sale.
(b) If each of the following articles is sold or offered for sale in the same pattern, the classification hereunder in subheadings 6911.10.35, 6911.10.37, 6911.10.38, 6912.00.35 or 6912.00.39, of all articles of such pattern shall be governed by the aggregate value of the following articles in the quantities indicated, as determined by the appropriate customs officer under section 402 of the Tariff Act of 1930, as amended, whether or not such articles are imported in the same shipment:
12 plates of the size nearest to 26.7 cm in maximum dimension, sold or offered for sale, 12 plates of the size nearest to 15.3 cm in maximum dimension, sold or offered for sale, 12 tea cups and their saucers, sold or offered for sale, 12 soups of the size nearest to 17.8 cm in maximum dimension, sold or offered for sale, 12 fruits of the size nearest to 12.7 cm in maximum dimension, sold or offered for sale, 1 platter or chop dish of the size nearest to 38.1 cm in maximum dimension, sold or offered for sale, 1 open vegetable dish or bowl of the size nearest to 25.4 cm in maximum dimension, sold or offered for sale, 1 sugar of largest capacity, sold or offered for sale, 1 creamer of largest capacity, sold or offered for sale.
If either soups or fruits are not sold or offered for sale, 12 cereals of the size nearest to 15.3 cm in maximum dimension, sold or offered for sale, shall be substituted therefor.
(c) The percentage of water absorption of cast and jiggered ceramic articles of the same pattern, which are "available in specified sets" and which are imported together in a ratio of at least 5 jiggered articles to 1 cast article in the same shipment shall be the average water absorption of such cast and jiggered articles, of the same pattern in the shipment, which average absorption shall be deemed to be equivalent to 5 percent of the water absorption of a representative sample of such cast articles plus 95 percent of the water absorption of a representative sample of such jiggered articles.
7. For the purposes of headings 6911, 6912 and 6913, those provisions which classify merchandise according to the value of each "article," an article is a single tariff entity which may consist of more than one piece. For example, a vegetable dish and its cover, or a beverage pot and its lid, imported in the same shipment, constitute an article.
Chapter 69 — Statistical Notes
US statistical reporting only. NOT classification law.
1. For the purposes of headings 6904 and 6905, a "heat insulating" article, whether or not shaped, is one having a specific gravity of 1.2 or less and designed to impede or resist the flow of heat at temperatures above 870°C.
2. For the purposes of heading 6904:
(a) The term "solid bricks" refers to bricks containing not more than 25 percent voids.
(b) The term "hollow bricks" refers to bricks containing more than 25 percent voids.
Notes are reproduced from the published tariff schedule. They govern classification, but reading them is not the same as applying them to your goods — that is what a broker or a binding ruling is for.
Other chapters that mention heading 6903
An exclusion pointing into this heading from another chapter is as decisive as one in your own, and it is the one nobody finds by reading their own chapter.
(a) Headings 6904 to 6914 apply only to such products other than those classifiable in headings 6901 to 6903;
1. For the purposes of headings 6902 and 6903, the term "refractory" is applied to articles which have a pyrometric cone equivalent of at least 1500°C when heated at 60°C per hour (pyrometric cone 18). Refractory articles have special properties of strength and resistance to thermal shock and may also have, depending upon the particular uses for which designed, other special properties such as resistance to abrasion and corrosion.
(c) Refractory goods of heading 6903; ceramic wares for laboratory, chemical or other technical uses, of heading 6909;
Other subheadings under 6903
Elsewhere in chapter 69
Importing 6903.10 into
Each guide covers how duty and tax are assessed there, the authority with jurisdiction, and what catches importers out.
Common questions
What is HS code 6903.10?
6903.10 covers Containing by weight more than 50 percent of free carbon. It sits under heading 6903 (Other refractory ceramic goods (for example, retorts, crucibles, muffles, nozzles, plugs, supports, cupels, tubes, pipes, sheaths, rods and slide gates), other than those of siliceous fossil meals or of similar siliceous earths) in chapter 69, ceramic products.
What is the US duty rate for 6903.10?
The Column 1 General rate is Free, from US national line 6903.10.00.00. That is the rate before any preference you can claim, and it does not include antidumping or countervailing duties, which are administered separately and can exceed it.
What is excluded from chapter 69?
2. This chapter does not cover: (a) Products of heading 2844; (b) Articles of heading 6804; (c) Articles of chapter 71 (for example, imitation jewelry); (d) Cermets of heading 8113;