Sourcing 4340 alloy steel bars from China
4340 alloy steel bars from China fall within heading 7228, with listed UK duty rates from 0% to 50%. Classify by processing condition, section and diameter, not the grade name alone. The hot-rolled anti-dumping measure concerns high-fatigue-performance rebar, so confirm the engineering-bar exemption. Cambridge China Bridge sources 4340 alloy steel bars.
Duty depends on how the bar is processed
Read from the UK Trade Tariff on 1 October 2026, heading 7228 covers other alloy steel bars and rods alongside sections and hollow drill bars. For the engineering-bar lines selected here, listed duty on goods from China ranges from 0% to 50%. Forged bars and cold-finished round bars of 80 mm or more show 0%; the selected hot-rolled lines and other selected cold-finished lines show 50%. Relevant steel quotas can provide 0% where available.
The supplied extract flags residual anti-dumping duty of 22.50 % on the selected hot-rolled lines. The published background identifies this as a measure on high-fatigue-performance concrete reinforcing bar, with an exemption for other bars. Ask your broker to confirm the exemption declaration for plain 4340 engineering bar. No countervailing duty, suspension or attached import control is listed for the selected lines in the supplied extract.
Confirm the commodity code using the mill certificate, actual processing route, section and diameter. Turning, peeling or grinding after rolling should be described to the broker rather than hidden under a generic grade description. See the wider engineering-bar guide. The UK carbon border adjustment mechanism applies from 1 January 2027; confirm with HMRC or your customs broker whether these alloy-bar lines are in scope, and ask the mill for emissions information when planning future imports.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Hot-rolled alloy round bars, diameter 80 mm or more | 7228 30 61 00 | 50% | 22.50% residual anti-dumping |
| Hot-rolled alloy round bars, under 80 mm, other | 7228 30 69 99 | 50% | 22.50% residual anti-dumping |
| Other alloy steel bars, not further worked than forged | 7228 40 90 00 | 0% | None |
| Cold-formed or cold-finished alloy round bars, diameter 80 mm or more | 7228 50 61 00 | 0% | None |
| Cold-formed or cold-finished alloy round bars, under 80 mm | 7228 50 69 00 | 50% | None |
| Other cold-formed or cold-finished alloy steel bars | 7228 50 80 00 | 50% | None |
Specify the 4340 grade and delivery condition
Write the governing grade specification and edition into the order, together with chemical composition acceptance criteria. Describe whether the bar is hot-rolled, forged, cold-finished, peeled or ground, and whether it is supplied annealed or quenched and tempered. Agree diameter, length, straightness, machining allowance, hardness and mechanical properties for the intended shaft or component. Require approval before any proposed equivalent grade is substituted.
Ask for a mill inspection certificate linked to each heat, showing chemistry, delivery condition and mechanical test results. Agree ultrasonic inspection and surface-defect acceptance where internal soundness matters. Also obtain evidence of the steel input's origin and processing history: covered Russian-origin steel processed through China can be prohibited from UK import. Government guidance says traders should be prepared to provide supply-chain documentation.
Worked duty example
Illustrative example, not a quote: Illustrative order: 20 tonnes of hot-rolled 4340 round bar under 80 mm, for machining under 7228 30 69 99, invoiced at £18,000 free on board, with £2,000 of freight and insurance to the UK. The customs value is £20,000. Duty at 50% is £10,000. Import VAT at 20% is charged on the customs value plus duty, £30,000, so it is £6,000. Import taxes total £16,000; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £10,000 of duty. The import duty and VAT guide explains each step.
Inspection checklist
Heat identity: match bar and bundle markings to the mill certificate, packing list and test samples; retain identity when bars are cut.
Chemistry and condition: check the reported composition against the ordered 4340 specification and verify sample chemistry, hardness and heat-treatment records.
Dimensions and surface: measure diameter, ovality, length and straightness; inspect for seams, cracks, scale, rust and end damage, allowing for the agreed machining stock.
Internal soundness and packing: review the agreed ultrasonic results and sample identification; check dry protective wrapping, secure bundles and handling damage. Use an agreed inspection brief.
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What goes wrong
A certificate saying only 4340 can leave the governing specification and delivery condition unresolved. Mixed heats, an unapproved substitute or uneven heat treatment can produce bars that machine or harden differently. Surface decarburisation and internal defects may appear only after machining. Agree acceptance criteria before production and keep each heat traceable through cutting and testing.
A quote based on the grade name alone can also miss the tariff distinction between rolled, forged and cold-finished bars. Quota availability can change the duty bill, while incomplete origin evidence can leave sanctions compliance unresolved. Have your broker review the product description and supporting documents before shipment, and use factory verification to check the mill's claimed production and testing capability.
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 4340 steel bars from China?
The selected lines show 0% to 50%. Forged bars and cold-finished rounds of 80 mm or more show 0%; selected hot-rolled and other cold-finished lines show 50%, with relevant quota relief where available.
Does 4340 engineering bar attract rebar anti-dumping duty?
The hot-rolled lines flag 22.50 % residual anti-dumping duty, but the measure concerns high-fatigue-performance rebar. Have your broker confirm the exemption declaration for engineering bar outside that scope.
What should the mill certificate show for 4340 bar?
Ask for the governing grade specification, heat number, chemical composition, delivery condition and mechanical test results. Match the certificate to the bars and agree any hardness or ultrasonic checks in the order.
Will UK carbon border charges affect alloy steel bars?
The UK carbon border adjustment mechanism applies from 1 January 2027. Confirm with HMRC or your customs broker whether these alloy-bar lines are in scope and which registration tests apply. Ask the mill for emissions information and review your expected imports before ordering.