3 Inch (76.2 mm) Fused Silica Wafers – Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); 76.2 mm format, TTV <5 um. No minimum order; DFM review included with every RFQ.
3 inch (76.2 mm) fused silica wafers are supplied as finished substrates: edge-rounded, cleaned and packed in wafer cassettes. The material brings near-zero thermal expansion and deep-UV transmission; the format brings SEMI-compatible handling.
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 |
| Diameter / format | 76.2 mm |
| Thickness | 0.3 – 1.0 mm typical |
| TTV | <5 um |
| Flat / notch | SEMI flat |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Capabilities and limits
One material, many routes: on Fused Silica we also quote cnc machining, lapping, ultrasonic machining, etching, and multi-step drawings are the norm rather than the exception.
Specification advice
Before sending the RFQ, check these against your drawing:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Specify flat or notch orientation relative to your device layout – regrinding orientation later scraps the wafer.
- 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.
Where these parts end up
Orders for 3 inch (76.2 mm) fused silica wafers cluster in scientific instruments (reference flats, cells, prism mounts, stage inserts); laboratory instruments (cuvettes, sight glasses, stir-cell windows); medical diagnostics (flow cells, slides, microplate bottoms, cuvette windows). 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 CNC machining capability, fused silica wafers 2-12 inch, machining tolerance guide.
Common questions
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
What tolerances are achievable on Fused Silica parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Its hardness and brittleness demand diamond tooling and controlled feeds.
What thickness range do you stock for Fused Silica?
Standard stock spans 0.10 – 50 mm, with blanks up to 450 x 450 mm. Other formats are sourced per order.
How does Fused Silica behave under heat?
CTE is 0.55 x 10^-6 /K and continuous service reaches 1,100 C continuous, which is what drives its use where near-zero thermal expansion matters.
Specifications on this page were last reviewed by our engineering team in October 2026.