Commercial Quality Windows, Circular, S1-UV Grade Fused Silica

Esco PN:
  • $ 1386

Diameter Tolerance

+/- 0.125 mm

Thickness Tolerance

+/- 0.125 mm

Surface Accuracy

≤ 2λ per inch

Surface Quality

60-40 Scratch-Dig or better




Fine ground and safety beveled*

Clear Aperture


*parts under 25.4mm in diameter may not have beveled edges

Commercial windows are used for sight glasses, instrument windows, beamsplitter substrates, vacuum windows and welding window substrates. Esco carries a complete inventory of circular commercial quality windows of S1-UV Grade Fused Silica.  Windows are polished both sides with ground edges. 

Don't see a part that matches exactly what you need, perhaps you'd like to modify a dimension or add a coating?  Use our fast online quote tool to find out what a custom part would cost. 


Ask a Question
  • What would be the weight of a window 20 inches diameter, 2 inches thick?

    Hello Mike, thank you for your question. The density of Fused Silica is 2.2046 grams/cubic centimeter. Which leads us to our calculation of 20 inch diameter window at 2” thick would be 50.05 lbs. It’s a good sized window and if you’d like a custom quote please follow this link to our custom quote tool and we should have a cost back to you quickly. 

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