Sourcing ball screws from China

Ball-screw duty and related components

Heading 8483 covers mechanical transmission components, including ball or roller screws. The complete ball-screw line is 8483 40 30 90. The other table rows cover related bearing housings and housing parts supplied separately, rather than alternative codes for complete ball screws.

Read from the UK Trade Tariff on 3 October 2026, ball or roller screws under 8483 40 30 90 carried 0% duty from China. The selected related components carried duties ranging from 0% to 6%. The supplied tariff facts record no anti-dumping or countervailing duties, tariff suspensions or attached import controls for these selected lines.

Send the drawing, assembly contents and intended function to your customs broker to confirm the commodity code. For other components within this heading, see gearboxes and transmission parts.

Specify the screw, nut and machined ends together

Specify screw diameter, lead, usable travel, overall length, thread direction and rolled or ground manufacture. State the required lead accuracy, axial backlash or preload, operating load, speed and duty cycle. Include a drawing of the bearing journals, shoulders, coupling end and nut mounting flange.

Agree the nut design, ball return arrangement, seals, lubricant and whether supports are included. Ask for measurement records tied to the supplied screw and nut. Approve a sample in the intended mounting arrangement before ordering the batch. For the assembled machine, HSE states that guards or protective devices are required where risks persist.

Worked duty example

Illustrative example, not a quote: Illustrative order of 40 ball-screw and nut assemblies; values are illustrative under 8483 40 30 90, invoiced at £8,000 free on board, with £1,200 of freight and insurance to the UK. The customs value is £9,200. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £9,200, so it is £1,840. 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: measure machined ends, bearing seats, shoulders, nut flange and usable travel against the approved drawing; trial-fit the intended supports and coupling.

Motion: measure axial backlash, lead accuracy and running torque using the agreed method; check for tight spots throughout travel and test a sample under the intended load.

Materials: match material and heat-treatment records to the batch; check agreed hardness readings and inspect raceways for pitting, burrs or corrosion.

Arrival: check that screws are supported inside the packaging, nuts remain secured and lubricant is present as agreed. Record bent shafts, impact marks and missing accessories before installation. Plan quality inspection before dispatch as well.

What goes wrong

A matching catalogue description can conceal different preload, lead accuracy or end machining. The nut may feel smooth without load yet bind after mounting because the screw and supports are misaligned. Incorrect bearing seats or shoulder positions can prevent assembly even when the nominal screw diameter matches.

Excessive backlash affects positioning, while excessive preload can raise running torque and temperature. Bent shafts, damaged ball returns and corrosion can arrive unnoticed in weak packaging. Keep the approved drawing and sample as acceptance references, and investigate tight spots before powering the axis.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification.