Quick answer: CNC Machining Borosilicate Glass covers Borosilicate Glass (CTE 3.3 x 10^-6 /K, 360 nm – 2.0 um); CNC Machining to +/-0.01 mm positional. Prototypes ship in 5-10 working days.
Ask any process engineer what makes borosilicate glass difficult and the answer is specific: sheet stock carries more thickness variation than float wafer stock, so lapping is often the first step. Our cnc machining line is tooled around exactly that – 4-axis machining centers with diamond tooling and through-spindle coolant – holding +/-0.01 mm positional on parts from 0.5 – 50 mm thick.
Specification envelope
| 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 | CNC Machining |
| Working tolerance | +/-0.01 mm positional |
| Minimum feature | 0.4 mm slot width |
| Surface finish | Ra 0.4 um ground, optional polish |
| Thickness window | 0.5 – 50 mm |
| Edge condition | chamfered 0.1 – 0.5 mm as standard |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
What the process holds
CNC Machining earns its place through complex 3D geometry – pockets, steps, counterbores and compound edges in one setup. Its boundary condition – internal corners carry a minimum radius equal to the smallest practical tool, typically R0.5 mm – is the first thing our DFM review checks.
Beyond this page, Borosilicate Glass routinely runs through polishing, dicing, sandblasting, edge grinding in our shop – most real parts combine two or three of these steps.
Getting the drawing right
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: internal corners carry a minimum radius equal to the smallest practical tool, typically R0.5 mm.
- 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.
Where these parts end up
The recurring buyers of cnc machining 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.
Useful companion pages: CNC machining capability, material selection guide, fused silica material guide.
Frequently asked questions
What equipment runs the cnc machining work?
4-axis machining centers with diamond tooling and through-spindle coolant.
Is there a minimum order for cnc machining 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 August 2026.