BOROFLOAT® 33 from SCHOTT AG is the world's first floated borosilicate flat glass. It combines superior quality and excellent flatness with outstanding thermal, optical, chemical and mechanical features. The chemical composition complies with DIN ISO 3585 and DIN EN 1748 T1 standards.

SCHOTT BOROFLOAT® 33 is a certified quality product manufactured to strict DIN ISO 3585 and DIN EN 1748 T1 standards. SCHOTT's patented float process guarantees uniform thickness (±0.05mm tolerance), exceptional optical quality and surface flatness. Based on our testing of various generic borosilicate glasses, quality varies significantly - we've observed air bubbles, uneven surfaces and waviness in many alternatives, although their thermal properties may be adequate. Every batch of BOROFLOAT® 33 comes with a quality certificate ensuring consistently high standards.

BOROFLOAT® 33 has exceptional thermal properties: Linear thermal expansion coefficient α₂₀/₃₀₀°C = 3.3 × 10⁻⁶ K⁻¹, transformation temperature Tg = 525°C, annealing point = 560°C, and softening point = 820°C. It withstands continuous temperatures up to 450°C. Thermal shock resistance (RTS) depends on thickness: 3.8mm = 175K, 6.5mm = 155K, 11mm = 142K.

BOROFLOAT® 33 excels in high-temperature applications due to its extremely low thermal expansion (3.3 × 10⁻⁶ K⁻¹), high thermal shock resistance (ΔT 140-175K depending on thickness), and continuous operating temperature up to 450°C. It withstands cracking significantly better than regular float glass - for comparison, standard soda-lime window glass has a thermal expansion coefficient of 9.0 × 10⁻⁶ K⁻¹ and thermal shock resistance of only about 40K.

BOROFLOAT® 33 has excellent optical properties: Refractive index nd = 1.471, Abbe number νe = 65.41, exceptional transparency in visible and near IR & UV range. Transmittance reaches >90% in visible light (380-780nm) for standard thicknesses. Low inherent fluorescence and minimal solarization tendency.

BOROFLOAT® 33 offers exceptional optical clarity with >90% transmittance in visible light, low fluorescence, minimal solarization, and excellent UV transmission. The refractive index of 1.471 and Abbe number of 65.41 make it perfect for precision optics, windows, and optical instruments.

While SCHOTT's state-of-the-art float process produces an exceptionally flat and smooth surface that far exceeds standard flat glass quality, it's important to understand that a float surface is not the same as a nano-level polished optical surface. The float process delivers excellent quality for display glass, windows, laboratory use, and many industrial applications. However, if you require nanometer-precision polished surfaces for lasers or precision optics, you'll need specially optically processed glass. BOROFLOAT® 33 serves as an excellent substrate material for these demanding optical treatments.

BOROFLOAT® 33 mechanical properties: Density ρ = 2.23 g/cm³, Young's modulus E = 63 GPa, Vickers hardness HV 0.1/20 = 6.2 GPa, and stress-optical coefficient K = 4.0 × 10⁻⁶ mm²/N. The glass shows excellent strength and durability for demanding applications.

BOROFLOAT® 33 offers exceptional chemical resistance: Hydrolytic resistance class HGB 1 (according to ISO 719), acid resistance class 1 (according to DIN 12116), and alkali resistance class A2 (according to ISO 695). It withstands most acids, bases, and solvents exceptionally well.

BOROFLOAT® 33 chemical composition (typical values): SiO₂ 81%, B₂O₃ 13%, Na₂O + K₂O 4%, Al₂O₃ 2%. This unique borosilicate composition provides the exceptional thermal and chemical properties that make it superior to regular soda-lime glass.

We stock BOROFLOAT® 33 in thicknesses: 2mm, 3.8mm, 6.5mm, 11mm, 15mm and 19mm. All thicknesses can be custom cut to any shape or dimension. For special applications, other thicknesses may be available on request.

BOROFLOAT® 33 is manufactured using SCHOTT's proprietary float process - the world's first floated borosilicate glass. This process ensures exceptional flatness, uniform thickness, and consistent quality. The float process eliminates surface defects and provides superior optical quality compared to traditional glass forming methods.

BOROFLOAT® 33 is versatile with numerous applications thanks to its thermal resistance. In 3D printing, it's a popular build plate material as its low thermal expansion (3.3 × 10⁻⁶ K⁻¹) keeps the surface flat during printing. Laboratories use it for test tubes, petri dishes, and reaction vessels due to its excellent chemical resistance (HGB 1 hydrolytic class). In optics, BOROFLOAT® 33 serves as protective windows with high transmittance (>90% in visible light) and UV transmission. LED lighting benefits from its ability to withstand continuous heat without yellowing. Industrial processes employ it as sight glasses up to 450°C. Microfluidics leverages its biocompatibility and smooth surface. In demanding applications like semiconductor photolithography and scientific instruments, BOROFLOAT® 33 is the standard choice for its technical properties and consistent quality.