SCHOTT BOROFLOAT® 33 Glass
SCHOTT BOROFLOAT® 33 is a UV-NIR transparent borosilicate float glass known for its excellent optical properties and smooth, low scatter surfaces. It is a high-performance, cost-effective material ideal for mass production of windows, mirrors, filters, display glass, and 3D build platforms. With outstanding thermal resistance and sharp impact crack resistance, it is perfect for challenging environments.
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Broad Spectral Range UV-VIS-NIR
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High Thermal Resistance (Shock & Gradient)
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Crack Resistant to Sharp Impac
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High Transparency/Color Neutral
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Low Thermal Expansion for Tight Seals
BOROFLOAT® 33 Basic properties:
- Good light transmittance, low fluorescence intensity and high ultraviolet and infrared transmittance.
- Low coefficient of thermal expansion, strong thermal shock resistance and long-term operating temperature up to 450℃.
- Good chemical stability, high resistance to corrosion of water, strong acid, strong alkali and organic material.
- Scratch resistance, high hardness and 20% lower density than ordinary sodium-calcium glass
- Low alkali content, can be used as an excellent electrical insulator.
| Technical parameters: | Chemical composition: | |
| Density (25℃) | 2.2g/cm2 |  |
| coefficient of expansion (ISO 7991) | 3.25′10-6k-1 | |
| Light transmittance | 91% | |
| Softening point | 820℃ | |
| Short-temm use <l0h | 550℃ | |
| Long-term use of l0h | 450℃ | |
| Refractive index (587.6nm) | 1.47140 | |
| Knoop hardness | 480 | |
BOROFLOAT® 33 Specifications and Thickness:
Thickness: 0.70 ~ 25.40mm Standard size: 1150 ‘850mm
Thickness: 3.30 ~ 15.00mm Standard size: 2300 ‘1700mm
Thickness: 16.00 ~ 25.40mm Standard size: 1700 ‘1300mm
Laser gauges are used to measure sheet thickness during production. Other available on request
Thermal properties of BOROFLOAT® 33:
Calibrated dimensions, thicknesses and tolerances.
The low coefficient of thermal expansion, strong resistance to thermal shock, and ability to withstand temperatures up to 450°C for long periods of time make BOROFLOAT® 33 particularly suitable for applications that require good temperature stability (e.g., the inner panels of pyrolytic self-cleaning ovens, the outer panels of high-power stage lights and high-power floodlights).
| Linear expansion | α (20 – 300 °C) | 3.25 x 10-6 K-1(ISO 7991) | Note: |
| Heat Capacity | Cp (20 – 100°C) | 0.83 KJ x (kg x K)-1 | This operating temperature is applicable only if the following values of in-plate temperature difference (RTG) and thermal shock resistance (RTS) are met simultaneously. |
| Thermal conductivity | λ (90°C) | 1.2 W x (m x K)-1 | |
| Operating temperature (long-term) | δ max (< 10 h) | 550°C | |
| Operating temperature (short-term) | δmax (≥ 10 h) | 450°C |
The same-sheet temperature difference (the performance of a piece of glass to with stand the temperature difference between the heating center and the cooler edge)
Test method: the area of about 25 × 25cm 2 glass plate is heated to a certain temperature, while its edges are kept at room temperature. The glass breakage rate due to thermal stress should be no more5%. Use before testing SIC 40-type coarse sandpaper polishes the glass plate to simulate extreme surface wear that may occur in use.
| RTG | |
| 1 – 100hours | 90 K |
| > 100hours | 80 K |
Thermal shock resistance (the performance of glass to withstand temperature quenching)
Test Method: the area of about20 × 20cm 2 glass plate is heated in a furnace and then used.50ml of cold water (room temperature) was poured over the center to cool. The breakage rate of the glass should not be greater5%. Use before testingSIC 220 coarse sandpaper polishes the glass plate to simulate the surface condition after actual use.
| Glass thickness | |
| ≤ 3.8mm | 175 K |
| 5.0 – 5.5mm | 160 K |
| 6.5 – 15.0mm | 150 K |
| > 15.0mm | 125 K |
BOROFLOAT® 33
| Work Point | 104 dPas | 1270°C |
| Softening Point | 10 7.6 dPas | 820°C |
| Annealing Point | 10 13 dPas | 560°C |
| Strain Point | 10 14.5 dPas | 518°C |
| Transition Temperature (Tg) | 525°C |
BOROFLOAT® 33 Optical Characteristics:
BOROFLOAT® 33is a clear, colorless glass. Excellent transmission in the ultraviolet and visible near-infrared light range makes BOROFLOAT® 33 has become a kind of application in a variety of floodlights, high-power spot lights and sunbeds (operating temperature up450 ℃) ideal material.BOROFLOAT® 33 glass is very low, good surface quality is flat and uniform, can be widely used in optics, optoelectronics, photonics and analysis equipment and other fields.
| WavelengthΛ(nm) | 435.8 | 479.9 | 546.1 |
| Refractive Indexn | 1.48015 | 1.47676 | 1.47311 |
| WavelengthΛ(nm) | 589.3 | 643.8 | 656.3 |
| Refractive Indexn | 1.47133 | 1.46953 | 1.46916 |
| Abbe Constant | Ve=(ne-1)/(nF’-nC’) | 65.41 | |
| Refractive Index | nd(λ587.6 nm) | 1.47140 | |
| Dispersion | nF-nC | 71.4 × 10-4 | |
| Stress Optical Coefficient | K | 4.0 × 10-6mm2N-1MPa-1 |
BOROFLOAT® 33
Some materials are excited by high-intensity high-frequency shortwave and have the property of releasing electromagnetic radiation. This property is called fluorescence. It is affected by the purity and structural characteristics of the material, but also depends on the single pulse energy, pulse frequency and the excitation wavelength of the radiation.
BOROFLOAT® 33 is a highly transparent glass that exhibits very weak fluorescence in the visible wavelength range.
Selected standard lasers and wavelengths:
| Wavelength (nm) | Laser Medium | Wavelength (nm) | Laser medium | Wavelength (nm) | Laser medium |
| 308 | XeCI | 488 | Ar | 1047 | Nd:YLF |
| 325 | HeCd | 514.5 | Ar | 1053 | Nd:YLF |
| 337 | N2 | 532 | Nd:YAG | 1064 | Nd:YAG |
| 350 | XeF | 632.8 | HeNe | 1153 | HeNe |
| 351.1 | Ar | 694.3 | Ruby | 1319 | Nd:YAG |
| 363.8 | Ar | 730-780 | Alexandrite | 1730 | Er:YLF |
| 427 | N2 | 850 | Er:YLF | 2060 | Ho:YLF |
| 441.6 | HeCd | 905 | GaAs | 10640 | CO2 |
BOROFLOAT® 33 Electrical Characteristics:
Due to the low alkali content,BOROFLOAT® 33 can be used as a high insulator, so it is suitable for applications at high temperatures (up450 ℃) under the need for materials with good non-conductive properties.
Because of the unique structure of borosilicate glass,BOROFLOAT® 33 has neutron absorption.
| Dielectric Constant | εr | (25 ℃,1 MHz) | 4.6 | |
| Leakage Constant | tan δ | (25 ℃,1 MHz) | 37 x 10-4 | |
| Resistivity Logarithm | lg ρ | 250 ℃ | 8.0 Ω x cm | |
| 350 ℃ | ||||
BOROFLOATBF33 is available in model Schott borosilicate glass:
| Thickness (mm) | Tolerance (mm) |
| 0.70 to 2.25 mm | ± 0.05 |
| 1.10 | ± 0.05 |
| 2.00 | ± 0.05 |
| 3.80 | ± 0.20 |
| 5.00 | ± 0.20 |
| 6.50 | ± 0.20 |
| 11.00 | ± 0.30 |
| 25.40 | ± 1.00 |
BOROFLOAT® Applications：
BOROFLOAT® chip applications
BOROFLOAT® Biotechnology applications
BOROFLOAT® optical lens applications
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