Quick answer: Grinding Fused Silica covers Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); Grinding to flatness to 5 um over 100 mm. Prototypes ship in 5-10 working days.
We grind Fused Silica daily, in thicknesses from 0.3 – 60 mm. The controlling numbers: flatness to 5 um over 100 mm working tolerance, thickness to +/-0.005 mm minimum features, and Ra 0.2 – 0.8 um 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 | Grinding |
| Working tolerance | flatness to 5 um over 100 mm |
| Minimum feature | thickness to +/-0.005 mm |
| Surface finish | Ra 0.2 – 0.8 um |
| Thickness window | 0.3 – 60 mm |
| Edge condition | ground perimeter, squareness 0.02 mm |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
What the process holds
Grinding earns its place through bringing thickness, flatness and parallelism into calibrated tolerance before polish. Its boundary condition – subsurface damage of 5 – 15 um must be budgeted and removed by polishing on optical faces – is the first thing our DFM review checks.
Beyond this page, Fused Silica routinely runs through polishing, sandblasting, etching, 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: subsurface damage of 5 – 15 um must be budgeted and removed by polishing on optical faces.
- 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 grinding fused silica cluster in microfluidic devices (chips, manifolds, via plates, bonded stacks); laser systems (windows, beam splitters, debris shields); scientific instruments (reference flats, cells, prism mounts, stage inserts). Background reading on the underlying material science: RP Photonics: fused silica.
The fastest route to a quote is geometry: use the 3D builder below, draw a dimensioned 2D drawing from it, or open the site-wide custom glass machining 3D + 2D builder for fully custom parts.
Related reading on this site: fused silica material guide, fused silica wafer applications, glass-bottom microplates.
Buyer questions, answered
What equipment runs the grinding work?
Rotary surface grinders and double-disc machines with diamond wheels.
Is there a minimum order for grinding 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.
Specifications on this page were last reviewed by our engineering team in September 2026.