Drilling Borosilicate Glass – Borosilicate Glass (CTE 3.3 x 10^-6 /K, 360 nm – 2.0 um); Drilling to +/-0.02 mm hole position. No minimum order; DFM review included with every RFQ.
The combination of Borosilicate Glass and Drilling comes up constantly in RFQs for a reason – the material offers thermal shock resistance, 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 | Borosilicate Glass (3.3 expansion group per ISO 3585) |
|---|---|
| Thermal expansion (CTE) | 3.3 x 10^-6 /K |
| Service temperature | 450 C continuous |
| Transmission range | 360 nm – 2.0 um |
| Density | 2.23 g/cm3 |
| Knoop hardness | 480 kg/mm2 |
| Refractive index | 1.473 @ 587 nm |
| Stock thickness | 0.50 – 30 mm |
| Maximum blank size | 600 x 400 mm |
| 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 |
DFM notes from the shop floor
Before sending the RFQ, check these against your drawing:
- Material note: sheet stock carries more thickness variation than float wafer stock, so lapping is often the first step.
- 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.
Capabilities and limits
The core strength of Drilling is through-holes, blind holes and countersinks at densities beyond 1,000 holes per part. The honest limit: hole-to-edge distance should stay above 1.5x thickness to protect strength. Both belong on the drawing before quoting, not after.
One material, many routes: on Borosilicate Glass we also quote grinding, sandblasting, coring, polishing, and multi-step drawings are the norm rather than the exception.
Application context
Orders for drilling borosilicate glass cluster in medical diagnostics (flow cells, slides, microplate bottoms, cuvette windows); scientific instruments (reference flats, cells, prism mounts, stage inserts); laboratory instruments (cuvettes, sight glasses, stir-cell windows). Background reading on the underlying material science: ISO 3585 borosilicate glass 3.3.
Dimensions still moving? Configure this part live in the 3D builder below, or open the full custom glass machining 3D builder to start from a blank canvas.
For adjacent specifications, see precision glass drilling, material selection guide, optical glass options.
Common questions
What tolerances are achievable on Borosilicate Glass parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Sheet stock carries more thickness variation than float wafer stock, so lapping is often the first step.
What thickness range do you stock for Borosilicate Glass?
Standard stock spans 0.50 – 30 mm, with blanks up to 600 x 400 mm. Other formats are sourced per order.
How does Borosilicate Glass behave under heat?
CTE is 3.3 x 10^-6 /K and continuous service reaches 450 C continuous, which is what drives its use where chemical durability 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.