Sourcing seamless finned steel tubes from China

Duty and classification for finned seamless tubes

Read from the UK Trade Tariff on 1 October 2026, the supplied heading 7304 lines cover seamless tubes, pipes and hollow profiles of iron other than cast iron, or steel. Every supplied line shows 0% duty for goods from China, with no listed anti-dumping or countervailing duty, steel measure, suspension or import control.

The table gives candidate descriptions for comparison, rather than a dedicated finned-tube code. Send your broker the finished drawing, tube and fin materials, manufacturing route, dimensions and intended use. For carbon-equivalent splits, provide chemical analysis using the tariff's specified formula. Confirm the commodity code before shipment. The seamless heat-exchanger tube guide covers the wider tube family.

Import VAT is normally 20%; see UK import duty and VAT. UK carbon border adjustment starts on 1 January 2027. For future steel orders, check your registration position and ask the supplier what mill and emissions information it can provide.

Specify the seamless core and fin construction

Specify the core tube grade, seamless manufacturing route, outside diameter, minimum remaining wall thickness, bore condition and heat treatment. Identify whether the fins are integral, welded, embedded or mechanically attached, and state their material separately. A seamless core can still have welded fins.

Put fin height, thickness, pitch, finned length, bare end lengths, straightness and end preparation on the drawing. Agree fin attachment acceptance, corrosion protection, cleaning, packing and any leak or pressure testing with the exchanger designer. For integral fins, make remaining wall thickness after fin forming an acceptance point.

For pressure service, establish whether the purchase is tube material or pressure equipment. The pressure equipment rules cover equipment and assemblies above 0.5 bar maximum allowable pressure. Ask the equipment designer to confirm the applicable classification and documentation before accepting a supplier's marking proposal.

Worked duty example

Illustrative example, not a quote: Illustrative order: 50 stainless seamless finned tubes, subject to classification confirmation under 7304 49 83 90, invoiced at £6,000 free on board, with £4,000 of freight and insurance to the UK. The customs value is £10,000. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £10,000, so it is £2,000. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Materials: match core and fin grades, heat numbers and mill test records to the purchase order; retain traceability after cutting and finning.

Geometry: measure core diameter, remaining wall, fin pitch and height, straightness and bare ends against the approved drawing.

Attachment and testing: inspect fin roots for gaps, cracks and loose attachment; review the agreed leak, pressure and non-destructive test records.

Arrival condition: check for crushed fins, bent lengths, wet packing, corrosion and blocked bores before releasing stock. Use the inspection guide to organise checks before dispatch and on receipt.

What goes wrong

Orders fail when the factory matches the overall diameter but changes the core wall or fin pitch. Poor fin contact can undermine heat transfer, damaged fins obstruct airflow, and incorrect bare ends prevent fitting into the tube plate. Approve a sample showing the actual fin construction and end geometry.

A test report for the plain tube does not demonstrate the condition after finning. Agree which checks follow fin attachment or forming, and keep the finished batch linked to the original material records. Support long lengths during transport and keep packing loads off the fins.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For repeat volumes, see container programmes.