Borofloat 33 With Rounded Corners – Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); R0.5 – R50 mm, matched to drawing. No minimum order; DFM review included with every RFQ.
When a drawing calls out Borofloat 33, three numbers matter before any machining starts: CTE of 3.25 x 10^-6 /K, service temperature to 450 C continuous, and a transmission window of 350 nm – 2.0 um. borofloat 33 with rounded corners here begin with those numbers and end with dimensional reports.
Specifications at a glance
| 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 | Rounded Corners |
| Capability | R0.5 – R50 mm, matched to drawing |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
What the process holds
Beyond this page, Borofloat 33 routinely runs through double-side polishing, edge grinding, dicing, etching in our shop – most real parts combine two or three of these steps.
These features are produced by cnc machining or edge grinding. Capability: R0.5 – R50 mm, matched to drawing. Design rule worth copying onto the drawing: R2 mm and larger survive handling far better than R0.5.
Design guidance
Three items decide most of the cost and lead time on this work:
- Material note: float tin side must be tracked when parts see coating or bonding steps.
- Feature rule: R2 mm and larger survive handling far better than R0.5.
- 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.
The full rules live in our tolerance design guide and holes and edges design guide.
Application context
borofloat 33 with rounded corners shows up across led packaging (groove covers, phosphor carriers, package windows); microfluidic devices (chips, manifolds, via plates, bonded stacks); mems devices (cap wafers, TGV substrates, motion-sensor lids). 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.
For adjacent specifications, see Borofloat 33 selection guide, wafer dicing process, glass wafer bonding.
Common questions
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 rounded corners?
R2 mm and larger survive handling far better than R0.5.
Is there a minimum order for borofloat 33 with rounded corners?
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.