Quick answer: Drilling Optical Glass covers Optical Glass (CTE 7.1 x 10^-6 /K, 350 nm – 2.0 um); Drilling to +/-0.02 mm hole position. Prototypes ship in 5-10 working days.
The combination of Optical Glass and Drilling comes up constantly in RFQs for a reason – the material offers striae and stress-birefringence control, and Drilling is the right way to get accurate geometry into it. Expect +/-0.02 mm hole position and exit-chip controlled below 0.1 mm.
The numbers
| 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 | Drilling |
| Working tolerance | +/-0.02 mm hole position |
| Minimum feature | 0.15 mm laser / 0.5 mm mechanical |
| Surface finish | exit-chip controlled below 0.1 mm |
| Thickness window | 0.1 – 30 mm |
| Edge condition | optional chamfered hole entry |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Design guidance
The shop-floor rules that matter here:
- Material note: index-certified blanks must be oriented and serialized through the shop to keep melt traceability.
- Process boundary: hole-to-edge distance should stay above 1.5x thickness to protect strength.
- 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.
What the process holds
Drilling earns its place through through-holes, blind holes and countersinks at densities beyond 1,000 holes per part. Its boundary condition – hole-to-edge distance should stay above 1.5x thickness to protect strength – is the first thing our DFM review checks.
Beyond this page, Optical Glass routinely runs through ultrasonic machining, lapping, laser cutting, grinding in our shop – most real parts combine two or three of these steps.
Application context
Orders for drilling optical glass cluster in scientific instruments (reference flats, cells, prism mounts, stage inserts); ccd inspection equipment (CCD cover plates, reference grids, stage glass); machine vision (camera windows, ring-light diffusers, calibration plates). 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 optical polishing capability, JGS1 quartz glass, CCD screening plates.
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 drilling hold?
+/-0.02 mm hole position with minimum features of 0.15 mm laser / 0.5 mm mechanical. Hole-to-edge distance should stay above 1.5x thickness to protect strength.
What equipment runs the drilling work?
Diamond core drills, ultrasonic assist and laser percussion heads.
Specifications on this page were last reviewed by our engineering team in July 2026.