Sourcing 4140 engineering bars from China
4140 engineering steel bars from China carry listed UK duty rates of 0% to 50%, depending on processing and diameter, with quota relief on applicable lines. Classify the actual bar rather than the grade name, and check steel-origin evidence for sanctions compliance. Cambridge China Bridge sources 4140 engineering steel bars.
Duty depends on processing and diameter
Read from the UK Trade Tariff on 1 October 2026, heading 7228 covers other alloy steel bars and rods, sections and hollow drill bars. This guide concerns 4140 engineering bar. The table gives candidate lines by processing and section; the grade name alone does not establish the commodity code. See the wider alloy steel bars guide.
The selected forged line and cold-finished round bar line for diameters of 80 mm or more show 0%; the other selected lines show 50%. The published heading guide explains 0% quota treatment for applicable steel-measure lines. The hot-worked lines list 22.50% residual anti-dumping duty, but that measure covers high-fatigue-performance rebar; other bars use additional code 8W01. The selected lines list no countervailing duties, suspensions or attached import controls.
Ask your broker to confirm processing history, cross-section, diameter and chemistry against the commodity code guidance, then check quota availability and the rebar exemption declaration before shipment. Import VAT is normally 20%; see UK import duty and VAT. The published heading guide also identifies these steel lines as within the UK carbon border adjustment mechanism from 1 January 2027.
| Goods | Commodity code | Duty | Anti-dumping or countervailing duty on China |
|---|---|---|---|
| Other alloy round bars, hot-worked only, diameter 80 mm or more | 7228 30 61 00 | 50% | 22.50% residual anti-dumping |
| Other alloy round bars, hot-worked only, diameter under 80 mm, excluding rebar | 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 |
| Other alloy round bars, cold-formed or cold-finished only, 80 mm or more | 7228 50 61 00 | 0% | None |
| Other alloy round bars, cold-formed or cold-finished only, under 80 mm | 7228 50 69 00 | 50% | None |
| Other alloy bars, cold-formed or cold-finished only, non-circular | 7228 50 80 00 | 50% | None |
Specify 4140 grade, condition and machining allowance
Write the agreed grade specification and chemistry into the purchase order. State whether the bar is supplied annealed or quenched and tempered, and specify hardness and mechanical properties for that delivery condition. Give diameter or section, cut length, straightness, surface finish and machining allowance. Require written approval before the mill substitutes another grade.
Ask for a mill inspection certificate linking each heat to chemistry, heat treatment and mechanical test results. Agree ultrasonic acceptance criteria where internal soundness matters for shafts or heavily loaded parts. Keep the bar markings traceable through cutting and storage; use factory verification to check the mill's production and testing capability.
Obtain supply-chain documents showing steel origin and processing history. UK sanctions prohibit imports of relevant iron and steel processed in third countries incorporating relevant Russian-origin iron and steel. Traders should be prepared to demonstrate supply-chain history with documents; a Chinese dispatch address alone does not resolve that check.
Worked duty example
Illustrative example, not a quote: 20 tonnes of 4140 hot-rolled round bar under 80 mm, excluding rebar; illustrative order 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
Identity: match bundle tags and bar markings to the purchase order and heat certificates; investigate mixed heats or missing identification.
Condition: compare sampled hardness and chemistry with the agreed specification and check that the certificate describes the supplied heat-treatment condition.
Dimensions: measure diameter or section, ovality, straightness and cut length; check the remaining allowance for machining.
Surface and soundness: check rust, seams, cracks, decarburisation and handling damage; review agreed ultrasonic results and moisture protection on arrival.
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What goes wrong
A bar described simply as 4140 arrives in the wrong heat-treatment condition, or a proposed substitute is accepted without checking the drawing. Mixed heats, missing markings, surface decarburisation and internal defects can leave material unsuitable after machining. Agree acceptance tests before production and quarantine questionable bundles on arrival.
Customs problems arise when the declaration follows the grade name rather than the processing route, quota availability changes before clearance, or the rebar exemption code is omitted. Missing steel-origin evidence also leaves sanctions checks unresolved. Reconcile the mill documents and broker's classification before dispatch.
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 4140 steel bars from China?
The selected lines show 0% to 50%. Forged-only bars and cold-finished round bars of 80 mm or more show 0%; other selected lines show 50%, with quota relief where applicable. Processing and diameter decide.
Does Chinese 4140 engineering bar attract anti-dumping duty?
The selected hot-worked lines list 22.50%, but the published heading guide limits the measure to high-fatigue-performance rebar. Other bars use additional code 8W01; have your broker confirm the declaration.
What should a 4140 mill certificate show?
Ask for the heat number, agreed grade specification, chemical composition, delivery condition and mechanical test results. Match the certificate to the actual bar markings and agree any additional testing before ordering.
Can I accept a substitute for 4140 bar?
Have your engineer compare the proposed grade, chemistry, delivery condition and test results with the drawing. Approve any substitution in writing before production; a supplier's equivalence claim is insufficient.