Sourcing sapphire optical windows from China

Duty on unmounted sapphire optical windows

Heading 9001 covers unmounted optical elements of any material, excluding glass elements that are not optically worked. For finished sapphire optical windows supplied without a mount, the relevant listed line is 9001 90 00 90. The table shows product variants sharing that tariff line.

Read from the UK Trade Tariff on 30 September 2026, the listed duty for goods from China under 9001 90 00 90 was 0%. The supplied record lists no anti-dumping or countervailing duty, tariff suspension or attached import control for this line.

Confirm the commodity code using the drawing, material, optical finish and mounting condition. For the wider heading context, see the unmounted fused silica optical windows guide.

Specify sapphire material, orientation and optics

Specify synthetic sapphire, crystal orientation, diameter or outline, thickness, clear aperture, surface flatness, parallelism or intentional wedge, edge bevel and permitted surface defects. State the operating wavelength band, angle of incidence and polarisation conditions. Ask the factory to explain how it measures each acceptance criterion.

For coated windows, define the coated faces, transmission or reflection acceptance limits and coating durability checks. Request material identification and optical test results tied to the supplied batch. Agree individual protective packing that prevents polished faces rubbing against each other.

For sales in Great Britain, conformity marking is only necessary where sector-specific regulations require it. Assess the intended application before requesting CE or UKCA marking. UK REACH generally covers substances in articles; ask for the substrate and coating composition to support an assessment of the applicable obligations.

Worked duty example

Illustrative example, not a quote: 100 unmounted sapphire optical windows, illustrative order under 9001 90 00 90, invoiced at £10,000 free on board, with £900 of freight and insurance to the UK. The customs value is £10,900. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £10,900, so it is £2,180. 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 sapphire identification and crystal orientation records to the order and batch.

Geometry: measure outline, thickness, bevel and parallelism or wedge against the drawing; check fit without forcing the window into its housing.

Optics: check flatness, scratches, pits and inclusions within the clear aperture, and measure transmission under the agreed wavelength and incidence conditions.

Packing: inspect individual protection, batch labels, edge chips and coating marks on arrival. Record defects through the agreed quality inspection process.

What goes wrong

A window can fit the housing yet fail optically because its crystal orientation, wedge or coating differs from the specification. A transmission result measured at the wrong wavelength or incidence angle does not establish acceptance for your application. Compare the test conditions as well as the reported result.

Polished faces can arrive scratched by packing debris, while chipped bevels can interfere with seating or sealing. Photograph defects before cleaning or assembly, retain the batch identity and agree replacement criteria before production.

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.