U.S. Customs and Border Protection · CROSS Database · 1 HTS code referenced
Primary HTS Code
8504.40.95
$1410.6M monthly imports
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Federal Register
1 doc
Related notices & rules
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2 cases
CIT & Federal Circuit
Ruling Age
18 years
Data compiled from CBP CROSS Rulings, Census Bureau Trade Data, Federal Register, CourtListener (CIT/CAFC) · As of 2026-04-28 · Updates monthly
The tariff classification of an Active Shaft Grounding (ASG) Unit from Canada
N019065 November 13, 2007 CLA-2-85:OT:RR:E:NC:N1:109 CATEGORY: Classification TARIFF NO.: 8504.40.95.80 Mr. Bryan C. Jensen Manager, Contract Administration & Imports Northrop Grumman Ship Systems, Inc. 1000 Access Road Mail Stop 1012-12 Pascagoula, MS 39567 RE: The tariff classification of an Active Shaft Grounding (ASG) Unit from Canada Dear Mr. Jensen: In your letter dated October 25, 1007 you requested a tariff classification ruling. The merchandise subject to this ruling is an Active Shaft Grounding (ASG) Unit. The ASG Unit, which contains no moving parts, converts alternating current (AC) input power, which cycles at 60 Hz, to a direct current (DC) output power. It utilizes its content of electronic components to provide a low resistance path for the current to bypass the shaft bearings, in effect, reducing or eliminating underwater electromagnetic signals that originate from current passing through a ship’s propeller shaft and shaft bearings. As stated on the manufacturer’s website, www.wrdavis.com/ASG.html: “The ASG system uses electronics to actively ground the shaft to the hull through a slip ring brush assembly. The system measures the shaft and hull potential through one slip ring assembly, and then uses this signal, after amplification, to control a high current power supply which draws a current out of the shaft through a second slip ring assembly. The circuitry reduces the variation in shaft-to-hull resistance, which in turn, results in small variation in the current between the cathodic protection anodes and the hull. The Extremely Low Frequency Electromagnetic (ELFE) signature is then virtually eliminated.” The first slip ring assembly is measuring the voltage between the propeller shaft and the hull. The term “signal” is an electrical current or an actual signal that is used for some type of simple communication with the ASG Unit. The “signal" is the “voltage” between the propeller shaft and the hull. The ASG Unit is an impedance amplifier that senses voltage (between the shaft and the hull) and controls a current driver to provide current to the rotating shaft. Essentially, the ASG Unit is a controlled power supply. The applicable subheading for the Active Shaft Grounding (ASG) Unit will be 8504.40.95.80, Harmonized Tariff Schedule of the United States (HTSUS), which provides for “Electrical transformers…: Static converters: Other: Other”. The general rate of duty will be 1.5 percent ad valorem. Duty rates are provided for your convenience and are subject to change. The text of the most recent HTSUS and the accompanying duty rates are provided on World Wide Web at http://www.usitc.gov/tata/hts/. This ruling is being issued under the provisions of Part 177 of the Customs Regulations (19 C.F.R. 177). A copy of the ruling or the control number indicated above should be provided with the entry documents filed at the time this merchandise is imported. If you have any questions regarding the ruling, contact National Import Specialist Linda M. Hackett at 646-733-3015. Sincerely, Robert B. Swierupski Director, National Commodity Specialist Division
Other CBP classification decisions referencing the same tariff code.
Trade notices, proposed rules, and final rules related to the tariff codes in this ruling.
Request for comments and notice of public hearing.
CIT and CAFC court opinions related to the tariff classifications in this ruling.