Sourcing tungsten disilicide powder from China

Duty on tungsten disilicide powder

Read from the UK Trade Tariff on 1 October 2026, heading 2850 covers hydrides, nitrides, azides, silicides and borides, excluding compounds that are also carbides. Tungsten disilicide powder falls within other silicides, 2850 00 60 95, carrying 4% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing duty and no suspension for this line.

The tariff attaches an import control for waste. For waste imported into England under notification controls, the Chinese exporter must apply to the competent authority in the country of dispatch for consent and follow its procedures. If buying reclaimed or spent powder, ask your customs broker to confirm whether this control applies and the full requirements for your shipment. The listed dangerous-chemical and waste export controls concern exports.

The table shows purchasing specifications sharing the same residual silicides code, rather than separate tariff subdivisions. Confirm composition, additives and physical form through finding your commodity code. For the wider heading context, see our molybdenum disilicide powder guide.

Specify phase, impurities and particle size

Specify tungsten disilicide rather than a generic tungsten silicide powder. Agree the phase composition, purity basis, limits for oxygen, carbon, free silicon and other metals, particle size distribution and specific surface area. Require the supplier to identify any additives and provide a batch certificate of analysis with test methods. Agree sealed packing and the conditions for storage and opening.

For Great Britain, confirm with HSE whether your annual imports of the substance require UK REACH registration and whether your own registration or an only representative is the appropriate route. Confirm when a safety data sheet should be provided and updated, and which Great Britain chemical classification and labelling requirements apply. Check these arrangements before ordering.

Worked duty example

Illustrative example, not a quote: Illustrative order: 2 tonnes of tungsten disilicide powder under 2850 00 60 95, invoiced at £50,000 free on board, with £2,000 of freight and insurance to the UK. The customs value is £52,000. Duty at 4% is £2,080. Import VAT at 20% is charged on the customs value plus duty, £54,080, so it is £10,816. Import taxes total £12,896; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £2,080 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Identity: check the purchase order, container labels and batch certificate all name tungsten disilicide and identify the same lot.

Analysis: test a representative independent sample for phase composition, purity and agreed impurities; compare the results with the batch certificate.

Particles: check particle size distribution and agglomeration against the approved sample, using the agreed measurement method.

Packing: check seals, liners, moisture ingress, net weight and batch traceability on arrival. Include these checks in your inspection brief.

What goes wrong

A purity figure can hide an unsuitable phase mixture or excess free silicon. A particle size result can conceal coarse agglomerates if the supplier uses a different sample preparation method. Poor seals can leave powder damp or caked. An attractive sample does not establish that the delivered batch meets the same specification.

Agree acceptance limits and sampling methods before production. Retain the approved sample and arrange independent batch testing before shipment. On arrival, keep damaged or mismatched containers separate pending investigation, and compare their contents with the retained sample before releasing them to production.

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.