Sourcing mica insulating washers from China

0% duty on mica insulating washers

Read from the UK Trade Tariff on 30 September 2026, heading 8547 covers insulating fittings for electrical machines, appliances or equipment, wholly of insulating material apart from minor metal components incorporated during moulding solely for assembly. Mica electrical insulating washers fit the other insulating fittings description under 8547 90 00 90, subject to confirmation against the actual construction and use.

The supplied tariff data shows 0% duty for goods from China, with no anti-dumping or countervailing duty, suspensions or attached import controls on this line. The table shows washer variants sharing the same tariff line. The separately described mica battery-module fire-protection component is not a general washer description.

Give your broker the drawing, material composition and intended electrical function to confirm the commodity code. For the wider product family, see insulating fittings.

Specify the mica, binder and clamping arrangement

Specify natural mica or bonded mica sheet, the mica grade, binder where used, and whether substitution is permitted. Put outside dimensions, hole diameter, hole position, thickness and tolerances on the drawing. Describe the mating surfaces, clamping arrangement, operating temperature and dielectric performance needed in the assembly.

Official guidance excludes component parts sold business-to-business from standalone RoHS scope. Parts incorporated into electrical products must nevertheless support the finished product's hazardous-substance compliance. Ask for material declarations covering the mica, binder and any coating, matched to the supplied grade. Agree relevant testing through testing and certification.

Worked duty example

Illustrative example, not a quote: 100,000 mica electrical insulating washers; illustrative order, not a quotation under 8547 90 00 90, 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

Material: match the mica grade, binder and coating to the approved specification and batch documents.

Dimensions: measure thickness, outside dimensions, hole diameter and hole position across samples from the shipment.

Edges and layers: inspect for cracks, chipped holes, loose flakes, delamination and contamination on insulating surfaces.

Assembly: trial-fit washers with the intended fasteners and mating parts; check damage after clamping and arrange dielectric testing where the application needs it.

What goes wrong

A washer can match the outline while differing in thickness, binder or mica construction. Chipped holes can worsen during tightening, and delaminated edges can shed material during assembly. An offset hole or uneven thickness can prevent the washer seating as intended.

Approve a sample in the actual assembly and record acceptable edge condition before ordering. Protect the washers from bending and moisture in transit, and keep material batches identifiable. Use the quality inspection guide to brief the inspection.

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.