Sourcing insulating fittings from China

0% duty

Read from the UK Trade Tariff on 27 September 2026, insulating fittings for electrical machines, appliances or equipment, being fittings wholly of insulating material apart from minor metal components for assembly, heading 8547, carried 0% on goods from China on every line: fittings of ceramics, of plastics, and of other materials including a listed mica component for lithium-ion battery modules. No line carried an anti-dumping measure.

Insulators for lines and substations are under heading 8546 (see our electrical insulators guide), and fittings with conducting parts such as terminals are classified as connectors, so confirm the commodity code.

Material performance and restricted substances

Plastic insulating parts are usually specified by flammability rating to UL 94, tracking resistance as a comparative tracking index to IEC 60112, and glow-wire performance to IEC 60695-2-11 where the end product standard calls for it. Parts going into electrical products sold in the UK must let the product meet the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations 2012, so ask for RoHS declarations.

Specifying insulating fittings

Specify material and grade (such as glass-filled nylon, PBT, steatite, alumina or mica), flammability and tracking ratings, dielectric strength, operating temperature, dimensions and tolerances from a drawing, inserts or threads, colour, and packing. For cable entry fittings, see plastic cable gland sourcing.

Worked duty example

An invented example rather than a quote: 100,000 plastic insulating stand-offs and bushes, commodity code 8547 20 00 00, bought for £15,000 free on board, with £700 of freight and insurance, so £15,700 is the value customs works from. No duty is due on insulating fittings; import VAT at 20% of £15,700 is £3,140. If you are VAT-registered, that VAT is normally reclaimable. See calculating UK import duty and VAT for the method.

Inspection checklist

Material: check the resin or ceramic grade on material certificates and that the flammability rating matches the drawing, and ask for a UL Yellow Card or test report where one is claimed.

Dimensions: measure critical dimensions and inserts on samples from each cavity or kiln batch, and check for cracks, voids and flash.

Electrical: have samples tested for dielectric strength where the application needs it, and check RoHS declarations before shipment.

What goes wrong

Insulating fitting orders fail on material and moulding. A cheaper resin without the required flammability rating is substituted, recycled material lowers tracking resistance, ceramic parts crack in firing, moulded parts warp or carry flash, and inserts pull out.

Lock the material grade in the order, test samples, and check each cavity. See our quality inspection guide.

Cambridge China Bridge sources insulating fittings for UK electrical and battery manufacturers, and can add material and dimension checks to an existing supplier. See existing suppliers.