Fused Silica Glass Spacers – Fused Silica (CTE 0.55 x 10^-6 /K, 185 nm – 2.5 um); Thickness 0.1 – 10 mm held to +/-0.005 mm. No minimum order; DFM review included with every RFQ.
A drawing for fused silica glass spacers is mostly a conversation about edges and datums. We produce them in Fused Silica at Thickness 0.1 – 10 mm held to +/-0.005 mm, with parallelism 2 um as the controlling tolerance, and finish the perimeter per spec.
Key parameters
| 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 |
| Geometry | Glass Spacers |
| Size envelope | Thickness 0.1 – 10 mm held to +/-0.005 mm |
| Key tolerance | parallelism 2 um |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Design guidance
Before sending the RFQ, check these against your drawing:
- Material note: its hardness and brittleness demand diamond tooling and controlled feeds.
- Hold the controlling dimension (parallelism 2 um) and let secondary dimensions carry standard tolerance – it is the single biggest cost lever.
- 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.
Process window
Beyond this page, Fused Silica routinely runs through drilling, lapping, double-side polishing, laser cutting in our shop – most real parts combine two or three of these steps.
Production route: grinding, lapping, double-side polishing – selected per geometry and volume. Edge condition: ground perimeter, squareness 0.02 mm.
Who orders this
Orders for fused silica glass spacers cluster in microfluidic devices (chips, manifolds, via plates, bonded stacks); scientific instruments (reference flats, cells, prism mounts, stage inserts); 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.
Useful companion pages: glass hole micromachining, glass-bottom microplates, Borofloat 33 selection guide.
Buyer questions, answered
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 sizes are available for glass spacers?
Thickness 0.1 – 10 mm held to +/-0.005 mm, held to parallelism 2 um.
Is there a minimum order for fused silica glass spacers?
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.
Specifications on this page were last reviewed by our engineering team in August 2026.