Sourcing extension springs from China

Duty on steel extension springs

Heading 7320 covers springs and leaves for springs of iron or steel. Cold-coiled extension springs fall within the coil tension spring description at 7320 20 85 90. The table shows product variants sharing that line, rather than separate tariff categories. For other spring types, see the steel springs guide.

Read from the UK Trade Tariff on 30 September 2026, the supplied lines all carry 0% duty for goods from China. The extension spring line has no listed anti-dumping or countervailing duty, suspension, steel measure or import control. Import VAT is separate from customs duty.

Confirm the material, manufacturing method and spring construction against the commodity code guidance. Give your customs broker the drawing and intended use, particularly for hot-worked springs or springs supplied within an assembly.

Specify initial tension and hook geometry

Specify the wire grade, wire diameter, coil diameter, body length and overall free length, stating how each length is measured. Define initial tension, loads at stated extended lengths, maximum working extension and acceptable permanent stretch. Show hook shape, opening, orientation and bend radius on the drawing; a photograph alone does not define the fit.

Agree the operating environment, finish, fatigue test and acceptance criteria before production. Ask for material certificates and heat-treatment records. For plated high-strength wire, agree evidence of treatment to address hydrogen embrittlement. Assess the spring in its intended mounting, including whether a hook can disengage during movement.

For springs imported into Great Britain for further manufacture, the finished-product manufacturer has sole and ultimate responsibility for ensuring compliance before placing that product on the market. Agree with your equipment customer which spring drawings and test records they need.

Worked duty example

Illustrative example, not a quote: Illustrative order of 18,000 extension springs under 7320 20 85 90, invoiced at £18,000 free on board, with £1,500 of freight and insurance to the UK. The customs value is £19,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £19,500, so it is £3,900. 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

Dimensions and hooks: measure wire and coil diameters, body and overall lengths, hook openings and orientation against the drawing. Check fit on the intended attachment.

Initial tension and load: use a calibrated spring tester to check the force needed to open the coils and the load at the specified working lengths. Check permanent stretch after the agreed extension test.

Material and finish: match certificates to the production batch, inspect hook bends for cracks and tool marks, and check the agreed coating and corrosion-test evidence.

Fatigue and packing: cycle samples in representative mountings and inspect the hook roots afterwards. Check that packing prevents tangling, bent hooks and abrasion. Agree the sampling and reporting through quality inspection.

What goes wrong

A spring can match the outside dimensions yet pull with the wrong force because initial tension differs. Incorrect hook orientation prevents installation, while sharp bends or tool marks can start fatigue cracks. Testing only the coil body can miss a weak hook; test through the actual attachment points.

Overextension leaves permanent stretch, and plating-related hydrogen embrittlement can cause early breakage. Tangled springs can arrive with distorted hooks or damaged coatings. Compare production samples with the agreed drawing and load results, and record failures before accepting the batch.

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.