Coring Borosilicate Glass – Borosilicate Glass (CTE 3.3 x 10^-6 /K, 360 nm – 2.0 um); Coring to diameter +/-0.05 mm. No minimum order; DFM review included with every RFQ.
The combination of Borosilicate Glass and Coring comes up constantly in RFQs for a reason – the material offers thermal shock resistance, and Coring is the right way to get accurate geometry into it. Expect diameter +/-0.05 mm and ground bore, honed option.
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 | Coring |
| Working tolerance | diameter +/-0.05 mm |
| Minimum feature | 2 mm core diameter |
| Surface finish | ground bore, honed option |
| Thickness window | 1 – 60 mm |
| Edge condition | entry/exit chamfer standard |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
DFM notes from the shop floor
Three items decide most of the cost and lead time on this work:
- Material note: sheet stock carries more thickness variation than float wafer stock, so lapping is often the first step.
- Process boundary: wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking.
- 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
Coring earns its place through large-diameter discs, rings and through-bores from plate stock up to 60 mm thick. Its boundary condition – wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking – is the first thing our DFM review checks.
Beyond this page, Borosilicate Glass routinely runs through lapping, sandblasting, cnc machining, laser cutting in our shop – most real parts combine two or three of these steps.
Where these parts end up
The recurring buyers of coring borosilicate glass: 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 + 2D builder below, or open the full custom glass machining 3D + 2D builder to start from a blank canvas.
For adjacent specifications, see material selection guide, glass sandblasting, glass in laser systems.
Common questions
What equipment runs the coring work?
Diamond core drills with rotary fixtures.
Is there a minimum order for coring borosilicate glass?
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.