Quick answer: Coring Borofloat 33 covers Borofloat 33 (CTE 3.25 x 10^-6 /K, 350 nm – 2.0 um); Coring to diameter +/-0.05 mm. Prototypes ship in 5-10 working days.
coring borofloat 33 is a materials problem before it is a machining problem. Borofloat 33 has float-glass flatness off the line and a Knoop hardness of 480 kg/mm2, so the coring recipe – feeds, coolant, tooling – differs from what works on ordinary float glass. The line runs diamond core drills with rotary fixtures and holds diameter +/-0.05 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 |
| Process | Coring |
| Working tolerance | diameter +/-0.05 mm |
| Minimum feature | 2 mm core diameter |
| Surface finish | ground bore, honed option |
| Thickness window | 1 – 60 mm |
| Edge condition | entry/exit chamfer standard |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
DFM notes from the shop floor
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.
- Process boundary: wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking.
- 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.
Capabilities and limits
The core strength of Coring is large-diameter discs, rings and through-bores from plate stock up to 60 mm thick. The honest limit: wall thickness between adjacent cores should exceed 2 mm to avoid bridge cracking. Both belong on the drawing before quoting, not after.
One material, many routes: on Borofloat 33 we also quote drilling, edge grinding, lapping, laser cutting, and multi-step drawings are the norm rather than the exception.
Who orders this
The recurring buyers of coring borofloat 33: microfluidic devices (chips, manifolds, via plates, bonded stacks); 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 glass wafer coring, wafer dicing process, tolerance design guide.
Frequently asked questions
What equipment runs the coring work?
Diamond core drills with rotary fixtures.
Is there a minimum order for coring borofloat 33?
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.