Borofloat 33 With Countersunk Holes – Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); 82/90 degree, depth +/-0.05 mm. No minimum order; DFM review included with every RFQ.
Buyers come to borofloat 33 with countersunk holes with two kinds of parts: catalog-adjacent blanks that need accurate finishing, and genuinely custom geometry. We quote both from the same dataset – SCHOTT float production, wafer grade stock in 0.70 – 25.4 mm, blanks to 500 x 500 mm.
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 |
| Feature | Countersunk Holes |
| Capability | 82/90 degree, depth +/-0.05 mm |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Specification advice
Before sending the RFQ, check these against your drawing:
- Material note: float tin side must be tracked when parts see coating or bonding steps.
- Feature rule: countersink diameter within 2.5x hole diameter.
- 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.
Process window
Beyond this page, Borofloat 33 routinely runs through laser cutting, sandblasting, edge grinding, coring in our shop – most real parts combine two or three of these steps.
These features are produced by drilling or cnc machining. Capability: 82/90 degree, depth +/-0.05 mm. Design rule worth copying onto the drawing: countersink diameter within 2.5x hole diameter.
Typical applications
borofloat 33 with countersunk holes shows up across microfluidic devices (chips, manifolds, via plates, bonded stacks); mems devices (cap wafers, TGV substrates, motion-sensor lids); machine vision (camera windows, ring-light diffusers, calibration plates). Background reading on the underlying material science: SCHOTT BOROFLOAT product page.
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: Borofloat 33 selection guide, wafer dicing process, glass sandblasting.
Frequently asked questions
Is there a minimum order for borofloat 33 with countersunk holes?
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.