Sourcing insulating motor slot wedges from China

0% duty on qualifying insulating slot wedges

Heading 8547 covers insulating fittings for electrical machines, appliances and equipment, wholly of insulating material apart from minor metal components incorporated during moulding solely for assembly. This guide concerns motor slot wedges qualifying as those fittings. The table shows product variants, with repeated codes where variants share a material line.

Read from the UK Trade Tariff on 30 September 2026, qualifying plastic fittings under 8547 20 00 00 and other insulating fittings under 8547 90 00 90 carry 0% duty for goods from China. The supplied record lists no anti-dumping or countervailing duty, suspension or attached import control. Import VAT is separate and normally charged at 20%.

Send the material composition, cross-section drawing and intended function to your customs broker to confirm the commodity code. A composite's commercial name alone does not establish its classification. See the switchgear barriers guide for related fittings within the wider heading, and import duty and VAT for the calculation method.

Specify the wedge profile and insulation material

Provide the motor slot drawing and specify wedge width, thickness, length, taper, edge radius, straightness and tolerances. State the resin, reinforcement or laminate construction, material grade and permitted machining direction. Agree the insertion method and retention check using a representative slot and the intended winding insulation.

Specify operating temperature, dielectric strength, mechanical strength and compatibility with the winding varnish and curing process. Approve samples after the intended assembly and curing process. Require batch material evidence and reports matching the supplied construction; a report for a different resin or laminate thickness does not establish the ordered wedge's performance.

For supply into Great Britain, official guidance excludes component parts sold business-to-business from RoHS scope. Assess the finished electrical product's hazardous-substance obligations separately and obtain material declarations for its assembler. Check the UK REACH Candidate List when reviewing material composition: inclusion of a substance brings supplier obligations. Arrange any agreed verification through testing and certification.

Worked duty example

Illustrative example, not a quote: Illustrative mixed-profile batch of plastic insulating motor slot wedges under 8547 20 00 00, invoiced at £15,000 free on board, with £700 of freight and insurance to the UK. The customs value is £15,700. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £15,700, so it is £3,140. 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

Profile: measure the cross-section, length and straightness against the drawing; trial-fit samples in the representative slot and check insertion and retention.

Edges and structure: inspect for sharp edges, machining burrs, cracks, exposed fibres and laminate separation that could damage winding insulation.

Material and performance: match batch certificates to the agreed construction and check agreed dielectric and mechanical test results against the supplied material.

Arrival and packing: check for moisture, bowed wedges and transit damage; confirm that pack labels identify profile, material grade and batch. Use the quality inspection guide to plan sampling.

What goes wrong

A wedge can match the nominal width yet bind because its taper, edge shape or straightness differs from the drawing. A loose wedge may fail the agreed retention check. Rough cut edges and exposed fibres can scrape winding insulation during insertion, while machining damage can start laminate separation.

Material substitution can change thermal, electrical and mechanical performance without an obvious colour change. A sample that fits before varnishing may behave differently after the intended curing process. Keep an approved sample and material specification, and verify bulk wedges using the same slot, assembly method and agreed tests.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For components and parts, see sourcing for manufacturers.