Borofloat 33 Round Glass Discs – Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); Diameter 2 – 450 mm, thickness 0.1 – 50 mm. No minimum order; DFM review included with every RFQ.
We build borofloat 33 round glass discs to print – Diameter 2 – 450 mm, thickness 0.1 – 50 mm – primarily in Borofloat 33. Typical use: viewing ports, wafer carriers and sensor windows.
The numbers
| Material | Borofloat 33 (SCHOTT float production, wafer grade) |
|---|---|
| Thermal expansion (CTE) | 3.25 x 10^-6 /K |
| Service temperature | 450 C continuous |
| Transmission range | 350 nm – 2.0 um |
| Density | 2.23 g/cm3 |
| Knoop hardness | 480 kg/mm2 |
| Refractive index | 1.471 @ 587 nm |
| Stock thickness | 0.70 – 25.4 mm |
| Maximum blank size | 500 x 500 mm |
| Geometry | Round Glass Discs |
| Size envelope | Diameter 2 – 450 mm, thickness 0.1 – 50 mm |
| Key tolerance | diameter +/-0.02 mm |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Specification advice
The shop-floor rules that matter here:
- Material note: float tin side must be tracked when parts see coating or bonding steps.
- Hold the controlling dimension (diameter +/-0.02 mm) and let secondary dimensions carry standard tolerance – it is the single biggest cost lever.
- 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.
What the process holds
Beyond this page, Borofloat 33 routinely runs through double-side polishing, etching, coring, ultrasonic machining in our shop – most real parts combine two or three of these steps.
Production route: coring, cnc machining, edge grinding – selected per geometry and volume. Edge condition: entry/exit chamfer standard.
Application context
borofloat 33 round glass discs shows up across optical sensors (sensor windows, filter caps, lens covers); machine vision (camera windows, ring-light diffusers, calibration plates); mems devices (cap wafers, TGV substrates, motion-sensor lids). Background reading on the underlying material science: SCHOTT BOROFLOAT product page.
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.
Engineers scoping this work usually also review wafer dicing process, Borofloat 33 selection guide, edge grinding overview.
Buyer questions, answered
Is there a minimum order for borofloat 33 round glass discs?
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.
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
What tolerances are achievable on Borofloat 33 parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Float tin side must be tracked when parts see coating or bonding steps.
Specifications on this page were last reviewed by our engineering team in September 2026.