Double-Side Polishing Borosilicate Glass – Borosilicate Glass (CTE 3.3 x 10^-6 /K, 360 nm – 2.0 um); Double-Side Polishing to TTV under 3 um. No minimum order; DFM review included with every RFQ.
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 double-side polishing line is tooled around exactly that – planetary double-side polishers with carrier plates – holding TTV under 3 um on parts from 0.1 – 10 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 | Double-Side Polishing |
| Working tolerance | TTV under 3 um |
| Minimum feature | Ra below 0.5 nm both faces |
| Surface finish | 60/40 to 20/10 both faces |
| Thickness window | 0.1 – 10 mm |
| Edge condition | edge-rounded before DSP |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Process window
Double-Side Polishing earns its place through wafer-grade parallelism and sub-nanometer roughness on both faces simultaneously. Its boundary condition – parts must be round or near-round; strongly asymmetric outlines wedge in the carriers – is the first thing our DFM review checks.
Beyond this page, Borosilicate Glass routinely runs through dicing, coring, cnc machining, polishing in our shop – most real parts combine two or three of these steps.
Specification advice
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: parts must be round or near-round; strongly asymmetric outlines wedge in the carriers.
- 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
double-side polishing borosilicate glass shows up across 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.
The fastest route to a quote is geometry: use the 3D builder below, draw a dimensioned 2D drawing from it, or open the site-wide custom glass machining 3D + 2D builder for fully custom parts.
Related reading on this site: glass sandblasting, material selection guide, glass-bottom microplates.
Buyer questions, answered
What equipment runs the double-side polishing work?
Planetary double-side polishers with carrier plates.
Is there a minimum order for double-side polishing 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.