Coring Fused Silica – Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); Coring to diameter +/-0.05 mm. No minimum order; DFM review included with every RFQ.
The combination of Fused Silica and Coring comes up constantly in RFQs for a reason – the material offers deep-uv transmission, and Coring is the right way to get accurate geometry into it. Expect diameter +/-0.05 mm and ground bore, honed option.
The numbers
| 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 |
| Process | Coring |
| Working tolerance | diameter +/-0.05 mm |
| Minimum feature | 2 mm core diameter |
| Surface finish | ground bore, honed option |
| Thickness window | 1 – 60 mm |
| Edge condition | entry/exit chamfer standard |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Getting the drawing right
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.
- Process boundary: wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking.
- 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.
Process window
Coring earns its place through large-diameter discs, rings and through-bores from plate stock up to 60 mm thick. Its boundary condition – wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking – is the first thing our DFM review checks.
Beyond this page, Fused Silica routinely runs through lapping, drilling, ultrasonic machining, laser cutting in our shop – most real parts combine two or three of these steps.
Where these parts end up
coring fused silica shows up across aerospace optics (sensor windows, star-tracker flats, radiation-tolerant ports); semiconductor equipment (view ports, wafer carriers, plasma rings, chamber windows); microfluidic devices (chips, manifolds, via plates, bonded stacks). Background reading on the underlying material science: RP Photonics: fused silica.
The fastest route to a quote is geometry: use the 3D configurator below, or the site-wide custom glass machining 3D builder for fully custom parts.
Related reading on this site: wafer dicing process, material selection guide, microfluidic glass applications.
Common questions
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.
What accuracy does coring hold?
Diameter +/-0.05 mm with minimum features of 2 mm core diameter. Wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking.
Specifications on this page were last reviewed by our engineering team in July 2026.