Borofloat 33 With Slots: Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); width from 0.4 mm, length any, ends R0.2 mm min. Single-piece prototypes to production volumes, quoted from your drawing.
Buyers come to borofloat 33 with slots 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.
Key parameters
| 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 | Slots |
| Capability | width from 0.4 mm, length any, ends R0.2 mm min |
| 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.
- Feature rule: slot web between features at least 1x thickness.
- 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 edge grinding, drilling, ultrasonic machining, dicing in our shop – most real parts combine two or three of these steps.
These features are produced by cnc machining or laser cutting. Capability: width from 0.4 mm, length any, ends R0.2 mm min. Design rule worth copying onto the drawing: slot web between features at least 1x thickness.
Typical applications
Orders for borofloat 33 with slots cluster in optical sensors (sensor windows, filter caps, lens covers); led packaging (groove covers, phosphor carriers, package windows); machine vision (camera windows, ring-light diffusers, calibration plates). 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 4 inch Borofloat wafers, Borofloat 33 selection guide, special-shaped glass plates.
Buyer questions, answered
How does Borofloat 33 behave under heat?
CTE is 3.25 x 10^-6 /K and continuous service reaches 450 C continuous, which is what drives its use where float-glass flatness off the line matters.
What is the design rule for slots?
Slot web between features at least 1x thickness.
Is there a minimum order for borofloat 33 with slots?
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.