Ultrasonic Machining Fused Silica: Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); Ultrasonic Machining to +/-0.02 mm form. Single-piece prototypes to production volumes, quoted from your drawing.
We ultrasonically machine Fused Silica daily, in thicknesses from 0.5 – 25 mm. The controlling numbers: +/-0.02 mm form working tolerance, 0.3 mm blind features minimum features, and matte machined surface off the machine. Where the drawing asks for more, downstream lapping and polishing take over.
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 |
| Process | Ultrasonic Machining |
| Working tolerance | +/-0.02 mm form |
| Minimum feature | 0.3 mm blind features |
| Surface finish | matte machined surface |
| Thickness window | 0.5 – 25 mm |
| Edge condition | crack-free feature edges |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
What the process holds
Ultrasonic Machining earns its place through blind cavities, non-round holes and stepped profiles that rotary tools cannot reach. Its boundary condition – material removal is slow, so it is reserved for features other processes cannot form – is the first thing our DFM review checks.
Beyond this page, Fused Silica routinely runs through grinding, drilling, sandblasting, dicing in our shop – most real parts combine two or three of these steps.
Design guidance
The shop-floor rules that matter here:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Process boundary: material removal is slow, so it is reserved for features other processes cannot form.
- 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.
The full rules live in our tolerance design guide and holes and edges design guide.
Where these parts end up
Orders for ultrasonic machining fused silica cluster in ccd inspection equipment (CCD cover plates, reference grids, stage glass); aerospace optics (sensor windows, star-tracker flats, radiation-tolerant ports); laboratory instruments (cuvettes, sight glasses, stir-cell windows). 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.
Engineers scoping this work usually also review fused silica material guide, wafer dicing process, custom FTO glass.
Buyer questions, answered
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 ultrasonic machining hold?
+/-0.02 mm form with minimum features of 0.3 mm blind features. Material removal is slow, so it is reserved for features other processes cannot form.
Specifications on this page were last reviewed by our engineering team in July 2026.