Sandblasting Optical Glass: Optical Glass (CTE 7.1 x 10^-6 /K, 350 nm – 2.0 um); Sandblasting to mask registration +/-0.1 mm. Single-piece prototypes to production volumes, quoted from your drawing.
We blast Optical Glass daily, in thicknesses from 0.7 – 25 mm. The controlling numbers: mask registration +/-0.1 mm working tolerance, 1 mm masked window minimum features, and uniform matte, gloss 4 – 8 GU off the machine. Where the drawing asks for more, downstream lapping and polishing take over.
Specifications at a glance
| Material | Optical Glass (N-BK7, H-K9L and filter glass sets) |
|---|---|
| Thermal expansion (CTE) | 7.1 x 10^-6 /K |
| Service temperature | 400 C (Tg 557 C) |
| Transmission range | 350 nm – 2.0 um |
| Density | 2.51 g/cm3 |
| Knoop hardness | 610 kg/mm2 |
| Refractive index | 1.5168 @ 587 nm |
| Stock thickness | 0.30 – 50 mm |
| Maximum blank size | 300 mm diameter |
| Process | Sandblasting |
| Working tolerance | mask registration +/-0.1 mm |
| Minimum feature | 1 mm masked window |
| Surface finish | uniform matte, gloss 4 – 8 GU |
| Thickness window | 0.7 – 25 mm |
| Edge condition | not applicable |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Capabilities and limits
The core strength of Sandblasting is uniform diffusing texture and masked logos or windows at panel scale. The honest limit: blasted faces lose roughly 30% bend strength; safety-critical faces get a post-etch. Both belong on the drawing before quoting, not after.
One material, many routes: on Optical Glass we also quote lapping, etching, drilling, ultrasonic machining, and multi-step drawings are the norm rather than the exception.
Getting the drawing right
Before sending the RFQ, check these against your drawing:
- Material note: index-certified blanks must be oriented and serialized through the shop to keep melt traceability.
- Process boundary: blasted faces lose roughly 30% bend strength; safety-critical faces get a post-etch.
- 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.
Who orders this
The recurring buyers of sandblasting optical glass: optical sensors (sensor windows, filter caps, lens covers); machine vision (camera windows, ring-light diffusers, calibration plates); laser systems (windows, beam splitters, debris shields). Background reading on the underlying material science: RP Photonics: optical glass.
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 AR optical windows, optical glass options, BF33 microfluidic chip.
Frequently asked questions
What tolerances are achievable on Optical Glass parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Index-certified blanks must be oriented and serialized through the shop to keep melt traceability.
What thickness range do you stock for Optical Glass?
Standard stock spans 0.30 – 50 mm, with blanks up to 300 mm diameter. Other formats are sourced per order.
How does Optical Glass behave under heat?
CTE is 7.1 x 10^-6 /K and continuous service reaches 400 C (Tg 557 C), which is what drives its use where certified refractive index and dispersion matters.
What accuracy does sandblasting hold?
Mask registration +/-0.1 mm with minimum features of 1 mm masked window. Blasted faces lose roughly 30% bend strength; safety-critical faces get a post-etch.
Specifications on this page were last reviewed by our engineering team in July 2026.