Sourcing molybdenum filaments from China

Duty and waste-control checks

Heading 8102 covers molybdenum and its articles, including waste and scrap. For evaporation filaments, distinguish wire supplied for forming from finished coils or shaped elements. Treat the table as candidate classifications rather than a ruling. Send the drawing, composition and supplied condition to your broker and confirm the commodity code.

Read from the UK Trade Tariff on 1 October 2026, every line in the supplied heading snapshot carried 0% duty for goods from China. The snapshot lists no anti-dumping or countervailing duty and no suspensions. The relevant duty range is therefore uniformly 0%. Import VAT is separate; see UK import duty and VAT.

The UK Trade Tariff attaches import and export waste controls to the selected wire and other-article lines. For shipments from China, ask your customs broker to confirm whether the material is waste and which requirements apply. If waste imported into England falls under notification controls, the exporter must apply to the competent authority in the country of dispatch for consent.

Filament geometry and chamber fit

Specify the molybdenum grade, purity, wire diameter, coil or basket shape, active length, terminal spacing and end geometry on an agreed drawing. Identify the chamber and clamp arrangement. Agree whether the filament supports the evaporation charge directly or heats a separate holder, and specify the intended charge material.

Ask for batch chemistry, the forming and annealing route, and an agreed surface-cleaning method. Define acceptable resistance and a sample trial in your chamber under your operating conditions. Record the charge, mounting method and heating sequence used for acceptance. For comparison with another filament material, see tungsten evaporation filaments.

Worked duty example

Illustrative example, not a quote: Illustrative order of 500 formed molybdenum evaporation filaments under 8102 99 00 00, invoiced at £2,000 free on board, with £800 of freight and insurance to the UK. The customs value is £2,800. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £2,800, so it is £560. 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 each batch identifier to its chemistry certificate and ordered grade. Arrange independent composition testing where needed.

Geometry: measure wire diameter, coil shape, terminal spacing and overall dimensions against the drawing. Check fit in the intended clamps without forcing the ends.

Surface and function: inspect for cracks, oxidation, oil and loose particles. Check resistance against the agreed acceptance range and trial samples in the intended chamber.

Packing: check that separate supports protect the coils and terminals from distortion and keep cleaned surfaces protected. Include these checks in the inspection brief.

What goes wrong

A filament can match the overall length yet have terminal spacing or coil geometry that does not fit the chamber. Forcing it into the clamps can damage the formed wire. Poorly controlled forming or annealing can leave brittle bends, while unsupported packing can flatten coils or bend terminals.

Oil, oxidation or loose particles can undermine a vacuum-process trial even when the dimensions pass. A chemistry certificate alone does not establish performance with your charge and heating sequence. Approve a mounted sample, record the trial conditions and retain it as the reference for repeat orders.

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.