U.S. Customs and Border Protection · CROSS Database · 1 HTS code referenced
Primary HTS Code
6806.10.0050
$11.7M monthly imports
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Ruling Age
35 years
Data compiled from CBP CROSS Rulings, Census Bureau Trade Data · As of 2026-04-28 · Updates monthly
The tariff classification of Rock Fiber or Mineral Wool invarious forms or shapes from Japan.
NY 856631 Oct 11, 1990 CLA-2-68:S:N:N1:236 856631 CATEGORY: Classification TARIFF NO.: 6806.10.0050 Mr. Matthew Chang Asst. Vice President C. Itoh & Co.(America) Inc. 335 Madison Ave. New York, NY 10017 RE: The tariff classification of Rock Fiber or Mineral Wool in various forms or shapes from Japan. Dear Mr. Chang: In your letter dated September 26,1990, you requested a tariff classification ruling. The prospective import, Rock Fiber ,is made from metallic ores which are fused at high temperatures and then centrifugally fiberized.The fusing of the following metallic ores results in an alumino-silicate or ceramic fiber: Silicon Oxide 38-42 percent by weight Aluminum Oxide 12-18 percent by weight Calcium Oxide 36-42 percent by weight Magnesium Oxide 4-8 percent by weight Iron Oxide less than 1 percent by weight The resultant product is used as an insulation, fireproofing, and noise control material. The product will be imported in various forms or shapes. The applicable subheading for the rock fiber will be 6806.10.0050, Harmonized Tariff Schedule of the United States (HTS), which provides for slag wool, rock wool, and similar mineral wools (including intermixtures thereof), in bulk, sheets or rolls. This ruling is being issued under the provisions of Section 177 of the Customs Regulations (19 C.F.R. 177). A copy of this ruling letter should be attached to the entry documents filed at the time this merchandise is imported. If the documents have been filed without a copy, this ruling should be brought to the attention of the Customs officer handling the transaction. Sincerely, Jean F. Maguire Area Director New York Seaport