Sourcing steel constant-force springs from China
Steel constant-force springs within heading 7320 carry 0% UK duty from China across the supplied tariff lines. Confirm the code from the actual construction and demonstrate compliance with relevant safety requirements before sale. Cambridge China Bridge sources steel constant-force springs.
Duty and classification for constant-force springs
Read from the UK Trade Tariff on 30 September 2026, heading 7320 covers springs and leaves for springs of iron or steel. Every supplied line carries 0% duty for goods from China. The supplied facts list no anti-dumping or countervailing duty, steel measure, suspension or attached import control.
The tariff descriptions do not name constant-force springs separately. Use the strip construction, coiling arrangement and drawing to assess the other-springs and flat-spiral categories. The helical rows are comparison categories for distinguishing wire-coil designs, rather than confirmed codes for constant-force strip springs. Confirm the commodity code before shipment.
For other spring types, see the steel springs guide. The worked order is illustrative and assumes the other-springs code has been confirmed. See UK import duty and VAT for the calculation method.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Other steel springs, a candidate category for constant-force strip springs | 7320 90 90 90 | 0% | None |
| Flat spiral springs, for comparison with the actual strip-spring design | 7320 90 10 90 | 0% | None |
| Helical tension springs, for distinguishing wire coils from strip springs | 7320 20 85 90 | 0% | None |
| Other helical springs, for comparison when checking the spring construction | 7320 20 89 90 | 0% | None |
Specify strip geometry and force over travel
Give the factory the steel grade, strip width and thickness, natural coil diameter, usable extension, mounting arrangement and end attachment drawing. State the permitted force variation across the working travel, including the initial pull-out region. Identify the intended drum or housing and the direction in which the strip unwinds.
Agree the cycling test, working environment, surface finish and acceptance criteria before production. Test samples in the intended mounting arrangement rather than accepting a force reading from an unspecified fixture. Before placing imported products on the market, you must demonstrate compliance with relevant regulations and safety requirements. Agree the application-specific evidence with the equipment maker.
Worked duty example
Illustrative example, not a quote: Illustrative order of 1,500 steel constant-force springs, assuming this code is confirmed under 7320 90 90 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
Force and travel: record the pull through the agreed working stroke, checking force variation, initial pull-out behaviour and smooth rewinding in the specified fixture.
Strip and attachments: measure width, thickness and coil diameter; inspect edges, holes and end fittings for burrs, cracks and distortion.
Material and durability: match material records to the batch and drawing; cycle samples using the agreed mounting, then check force drift, cracking and permanent deformation.
Packing and traceability: check that coils are restrained, separated and protected from moisture; match batch labels and test records to the delivered parts. Plan the checks through quality inspection.
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What goes wrong
A spring can meet a single force reading yet vary too much over the working stroke. Strip thickness, coil curvature and mounting friction can change the pull. A sample tested on the supplier's drum may behave differently in your housing, so approve the spring together with its mounting arrangement.
Burrs and damage around attachment holes can start cracks. Poor restraint in transit lets coils unwind or kink, while damp packing encourages corrosion. Record defects by batch and compare production samples with the approved drawing and force trace before accepting the shipment.
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.
Frequently asked questions
What is the UK import duty on steel constant-force springs from China?
The supplied heading 7320 lines carry 0% duty from China, with no listed anti-dumping or countervailing duty. Confirm the exact commodity code from the spring drawing.
Which commodity code covers constant-force springs?
The supplied tariff does not name them separately. Compare 7320 90 90 90 and 7320 90 10 90 with the actual construction, then ask your customs broker to confirm the classification.
What should I put on a constant-force spring drawing?
Specify steel grade, strip width and thickness, coil diameter, working travel, force tolerance, end attachments, mounting arrangement, finish and the agreed cycling test.
How do I check whether the spring force is consistent?
Measure pull across the agreed working stroke in the intended mounting fixture. Check initial pull-out, force variation and rewinding, then repeat the measurements after the agreed cycling test.