Quick answer: CNC Machining Fused Silica covers Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); CNC Machining to +/-0.01 mm positional. Prototypes ship in 5-10 working days.
We machine Fused Silica daily, in thicknesses from 0.5 – 50 mm. The controlling numbers: +/-0.01 mm positional working tolerance, 0.4 mm slot width minimum features, and Ra 0.4 um ground, optional polish 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 | CNC Machining |
| Working tolerance | +/-0.01 mm positional |
| Minimum feature | 0.4 mm slot width |
| Surface finish | Ra 0.4 um ground, optional polish |
| Thickness window | 0.5 – 50 mm |
| Edge condition | chamfered 0.1 – 0.5 mm as standard |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Process window
CNC Machining earns its place through complex 3D geometry – pockets, steps, counterbores and compound edges in one setup. Its boundary condition – internal corners carry a minimum radius equal to the smallest practical tool, typically R0.5 mm – is the first thing our DFM review checks.
Beyond this page, Fused Silica routinely runs through drilling, coring, dicing, laser cutting in our shop – most real parts combine two or three of these steps.
Specification advice
Before sending the RFQ, check these against your drawing:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Process boundary: internal corners carry a minimum radius equal to the smallest practical tool, typically R0.5 mm.
- 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.
Typical applications
The recurring buyers of cnc machining fused silica: laser systems (windows, beam splitters, debris shields); microfluidic devices (chips, manifolds, via plates, bonded stacks); mems devices (cap wafers, TGV substrates, motion-sensor lids). 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.
Useful companion pages: CNC machining capability, wafer dicing process, glass wafer bonding.
Buyer questions, answered
What equipment runs the cnc machining work?
4-axis machining centers with diamond tooling and through-spindle coolant.
Is there a minimum order for cnc machining fused silica?
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 August 2026.