Fused Silica

SILBOND® FW fused silica is an ultra high purity quartz manufactured by an electric arcing process that takes place at around 2000°C. One of its most outstanding qualities is the extremeley low thermal coefficient of expansion, being 0.5 x 10-6/K. Furthermore it has excellent thermal shock resistance, a high transformation temperature, high softening temperature, low thermal conductivity, good optical light transmission, corrosion resistance and a diffusion blocking effect against most substances. These properties make it an ideal material for use in electrical insulation, casting resin systems, electronics, precision casting and technical ceramics.

Various sizes and surface modifications are also possible to enhance the compataibility with the continuous media of the composite. 


    • High purity electrically fused silica.

    • Iron-free grinding process with subsequent air separation.

    • Various particle size distributions and surface treatments available.

    • Density of 2.2 g/cc.

    • Low coefficient of thermal expansion: 0.5 x 10-6/K


    • Improves dimensional stability over a range of temperature. Prevents thermal shock.

    • Excellent chemical resistance and barrier properties.

    • Low thermal conductivity.

    • High transformation temperature and softening point means that it is stable in high temperature applications.

    • Low electrical loss factor even after submersion in water.

Typical Applications

    • Electrical insulation.

    • Casting resin systems.

    • Electronics.

    • Precision casting.

    • Technical ceramics.

Featured grades with technical datasheets

A brief overview of the key grades is given below. You will find the Technical Datasheets (TDS) available for download. If you are looking for a Safety Datasheet (SDS) or Product Safety Information (PSI) then please get in touch by phone or via the contact buttons at the top of the page.

Should you not find what you are looking for here then please note that we have further grades available besides these. One of our Technical Sales team will be happy to help. All of the sales team are technically qualified and will be able to advise you on which product to choose. You can either call us, email us or fill in a quick form at the top of the page to get us to call you (Request a Callback). A sample can be requested via the button at the top of the page as well. Please note that by providing us with your contact details, you are agreeing for us to potentially contact you.

Related brochures & technical literature

You will find some of the key product brochures available for download below. There are more brochures available upon request. If you would like to discuss your enquiry further then please get in contact by phone or by filling in the "Request a Callback" form at the top of the page. Someone from the technical sales team will then call you within 24 hours, to discuss your project further.

High Performance Fillers in Epoxy Resin for Use in Medium High Voltage Tech

SILBOND® FW 12 EST shows a very low electrical loss factor before and after immersion in water. Similarly mechanical properties are also well maintained. This makes it ideal for use in medium-high voltage epoxy resin composites.

High Performance Fillers in Epoxy Resin for Use in Medium High Voltage Tech Brochure /