Customised machine part classification prevails over brush classification for tunnel boring equipment under the tariff headings.

An item specially designed and customised for use with tunnel boring machinery was held classifiable as a specific part under Chapter Heading 8431, because it was solely or principally suitable for machinery of Heading 8430 and performed a protective function for the machine. Although it resembled a brush, Chapter Heading 9603 applies to brushes of general application, not an article whose essential character is that of a machine part. The Revenue's proposed classification under Heading 9603 was rejected, and the item was treated as classifiable under Heading 8431 43 90.

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Issues: Whether the imported item "Tail Brush FIRC" was classifiable under Chapter Heading 8431 as a part suitable for use solely or principally with tunnel boring machinery, or under Chapter Heading 9603 as a brush constituting part of a machine.

Analysis: The competing entries were examined by comparing the scope of Chapter Heading 8431, which covers parts suitable for use solely or principally with machinery of headings 8425 to 8430, with Chapter Heading 9603, which covers brooms and brushes including brushes constituting parts of machines, appliances or vehicles. The item was found to be specially designed and customised for use with the tunnel boring machine, with the functional purpose of shielding the machine and restricting flow into it. Since the item was principally suitable for use with machinery falling under Heading 8430, it answered the description of a specific part under Chapter Heading 8431 rather than a brush of general application under Chapter Heading 9603.

Conclusion: The item was correctly classifiable under Chapter Heading 8431 43 90 and not under Chapter Heading 9603 50 00; the Revenue's classification was rejected.

Ratio Decidendi: Where an article is specially customised and suitable solely or principally for use with a particular machine, it is classifiable as a specific part of that machine even if it may also resemble a brush in form.

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