Custom High Borosilicate Glass Panels & Discs (Borosilicate 3.3)
(High Thermal Resistance | Low Thermal Expansion | CNC Ground Safety Edges | Custom Thickness & Shapes)
1. Product Overview & Key Engineering Highlights
Our Custom High Borosilicate Glass Panels (Borosilicate 3.3 / Pyrex grade) are engineered for demanding industrial sight glasses, chemical reactor observation windows, high-power LED luminaire covers, laboratory glassware, and home appliance touch panels.
Composed of high-purity silica and boron oxide, Borosilicate 3.3 glass features an ultra-low coefficient of linear thermal expansion ($3.25 \times 10^{-6}$ / K equivalent to $3.3 \times 10^{-6}$ / K), providing superior thermal shock resistance, excellent acid/alkali corrosion resistance, and high optical transmittance (>91%).
All glass panels are fabricated to tight tolerances based on customer CAD drawings (DXF, DWG, STEP, PDF) and finished with precision CNC safety edge grinding (safety arris / flat polished / 2.5D round bevels) to eliminate sharp burrs and micro-cracks.
Superior Thermal Stability: Continuous operating temperatures up to 450°C–500°C; maximum short-term thermal threshold up to 550°C.
Exceptional Thermal Shock Resistance: Withstands rapid temperature swings ($\Delta T$ up to 150°C–200°C) without cracking or warping.
High Optical Clarity & Transmittance: Over 91% visible light transmission with low optical dispersion.
Precision Safety Edge Grinding: CNC chamfered edges (C-edge / R-edge / arris) eliminate micro-flaws, dramatically reducing edge stress and assembly injury risks.
Chemical Durability: Outstanding resistance to water, strong acids, organic solvents, and neutral saline solutions (ISO 719 / ISO 695 compliant).
2. Comprehensive Technical Specifications
| Parameter / Property | Standard Value & Custom Range |
| Product Name | Custom High Borosilicate 3.3 Glass Panel |
| Base Material | High Borosilicate Float Glass (Boro 3.3 / Schott Borofloat 33 equivalent) |
| Thickness Range | 0.5mm, 1.1mm, 1.8mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm, 8.0mm to 25mm+ |
| Dimensional Tolerance | ± 0.05 mm to ± 0.1 mm (High-Speed CNC Milling / Waterjet) |
| Linear Thermal Expansion (CTE) | 3.3 x 10^-6 / K (20°C to 300°C) |
| Transformation Temperature (Tg) | 525°C to 560°C |
| Softening Point | Approx. 820°C |
| Continuous Operating Temp | Up to 450°C – 500°C |
| Short-Term Peak Temp | Up to 550°C |
| Thermal Shock Resistance ($\Delta T$) | 150°C to 200°C (e.g., sudden hot-to-cold quenching) |
| Optical Transmittance | >= 91.5% (Bare Substrate) / >= 95%–98% (with AR Coating) |
| Refractive Index (Nd) | 1.473 |
| Density | 2.23 g/cm³ (approx. 10% lighter than standard soda-lime glass) |
| Surface Hardness (Mohs / Knoop) | Mohs 6–7 / HK 480 |
| Edge Processing | Safety Arris Edge (45° micro-chamfer), Flat Polished, 2.5D C-edge / R-edge |
| Secondary Processing | Silk Screen Ceramic Printing, AR/AF Coating, Thermal Tempering, Step-milled Edges |
3. Thermal & Mechanical Performance Breakdown
Why Borosilicate 3.3 Beats Regular Float Glass in Heat Resistance:
Standard soda-lime glass has a high thermal expansion coefficient (~$9.0 \times 10^{-6}$ / K), making it vulnerable to thermal stress fractures at temperature differences above 50°C. High Borosilicate 3.3 expands at roughly one-third of that rate, easily enduring thermal gradients over 150°C without mechanical failure.
Safety Edge Processing Integrity:
Raw cut glass possesses microscopic edge micro-fissures that act as stress concentration points under thermal loads. Our CNC grinding and flame/mechanical polishing smooth these boundaries into polished safety arrises, boosting the overall mechanical and thermal load capacity by over 40%.
- Typical Applications & Use Cases
High-Power LED & Luminaire Fixtures: High-bay industrial lamps, stage spotlights, searchlights, explosion-proof light covers, and outdoor architectural floodlights.
Industrial & Pipeline Sight Glasses: Chemical reactor observation ports, boiler level gauges, furnace inspection ports, and petroleum pipeline sight windows.
Laboratory & Medical Equipment: Biological cultivation plates, microfluidic chips, autoclave viewing windows, and laboratory drying oven doors.
Home & Commercial Appliances: Oven front door viewing panels, microwave turntables, induction cooker touch panels, and fireplace glass barriers.
3D Printer Bed Plates: Ultra-flat, high thermal conductivity heated bed surfaces ensuring zero model warping.
5. Frequently Asked Questions (FAQ)
Q1: What is the difference between Borosilicate Glass and Soda-Lime (Float) Glass?
A: Borosilicate glass contains a high percentage of boron oxide ($\sim 13\%$), giving it a thermal expansion coefficient about one-third of soda-lime glass. This makes it far more resistant to high operating temperatures (up to 500°C vs. 150°C) and sudden thermal shock ($\Delta T$ 150°C vs. 50°C). It is also lighter and chemically more inert.
Q2: How does Borosilicate Glass compare to Quartz Glass?
A: Quartz glass (fused silica) offers higher temperature resistance (1100°C) and deep UV transmission, but is considerably more expensive and difficult to machine. Borosilicate glass provides the ideal, cost-effective balance for temperatures up to 500°C, high visible light transmission, and superior chemical durability.
Q3: Can Borosilicate Glass be physically tempered?
A: Yes. Borosilicate glass sheets with thicknesses $\ge 3.0\text{mm}$ can be physically tempered to further improve mechanical bending strength and impact resistance, while thinner sheets (0.5mm–2.0mm) can be chemically strengthened if required.
Q4: What types of safety edges can you grind on custom shapes?
A: We offer 45° safety arrissed edges (seamed edges), flat polished edges with micro-chamfers, 2.5D pencil/round edges, and stepped (rabbeted) ledges for O-ring gasket sealing. All edges are free of sharp burrs.
Q5: What file formats are supported for custom fabrication?
A: We accept standard 2D and 3D CAD drawing formats, including DXF, DWG, STEP, STP, IGES, and dimensioned PDF drawings.
6. Packaging & Global Export Protection
Surface Scratch Protection: Double-sided anti-static PE protective film or acid-free paper interleaving between individual panels.
Shock-Absorbing Inner Packaging: Custom-slotted high-density EPE foam cassettes preventing vibration and edge chipping.
Reinforced International Crates: Heavy-duty drop-tested corrugated cartons and fumigation-free wooden cases engineered for safe international sea and air shipping.
