Fused Silica Square Glass Windows: Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); 5 x 5 mm to 300 x 300 mm, thickness 0.3 – 25 mm. Single-piece prototypes to production volumes, quoted from your drawing.
We build fused silica square glass windows to print – 5 x 5 mm to 300 x 300 mm, thickness 0.3 – 25 mm – primarily in Fused Silica. Typical use: instrument viewports and detector covers.
Specifications at a glance
| Material | Fused Silica (JGS1 (UV), JGS2 (standard), JGS3 (IR)) |
|---|---|
| Thermal expansion (CTE) | 0.55 x 10^-6 /K |
| Service temperature | 1,100 C continuous |
| Transmission range | 185 nm – 2.5 um |
| Density | 2.20 g/cm3 |
| Knoop hardness | 500 kg/mm2 |
| Refractive index | 1.458 @ 587 nm |
| Stock thickness | 0.10 – 50 mm |
| Maximum blank size | 450 x 450 mm |
| Geometry | Square Glass Windows |
| Size envelope | 5 x 5 mm to 300 x 300 mm, thickness 0.3 – 25 mm |
| Key tolerance | side +/-0.03 mm |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Process window
Beyond this page, Fused Silica routinely runs through sandblasting, dicing, double-side polishing, ultrasonic machining in our shop – most real parts combine two or three of these steps.
Production route: cnc machining, polishing, edge grinding – selected per geometry and volume. Edge condition: chamfered 0.1 – 0.5 mm as standard.
Specification advice
Three items decide most of the cost and lead time on this work:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Hold the controlling dimension (side +/-0.03 mm) and let secondary dimensions carry standard tolerance – it is the single biggest cost lever.
- Over-specification is the quiet budget killer: a 20/10 scratch-dig face costs roughly three times an 80/50 face, so grade each surface individually.
For the complete framework, see the tolerance design guide and the holes and edges design guide.
Who orders this
fused silica square glass windows shows up across medical diagnostics (flow cells, slides, microplate bottoms, cuvette windows); laboratory instruments (cuvettes, sight glasses, stir-cell windows); scientific instruments (reference flats, cells, prism mounts, stage inserts). Background reading on the underlying material science: RP Photonics: fused silica.
Dimensions still moving? Configure this part live in the 3D + 2D builder below, or open the full custom glass machining 3D + 2D builder to start from a blank canvas.
For adjacent specifications, see fused silica wafers 2-12 inch, CNC machining capability, thickness and flatness guide.
Frequently asked questions
Is there a minimum order for fused silica square glass windows?
No. Single prototypes are accepted, and pricing steps down at 10, 100 and 1,000 pieces.
How fast can prototypes ship?
Machined prototypes ship in 5 – 10 working days. Coated or bonded parts add 1 – 2 weeks depending on queue slots.
What files do you need for a quote?
A dimensioned PDF plus DXF or STEP geometry. If only a sketch exists, our drawing review service formalizes it before quoting.
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
Specifications on this page were last reviewed by our engineering team in September 2026.