With the same chemical composition as BOROFLOAT® 33 and combining low thermal expansion, high thermal stability, good light transmission and chemical durability, it suits large-thickness industrial viewing windows and precision structural parts.
SUPREMAX® 33 uses a rolled process to deliver the large thicknesses that micro-float cannot cover, while retaining the thermal, optical and chemical properties of type 3.3 borosilicate glass.
Average coefficient of linear thermal expansion from 20–300 °C is 3.25 × 10⁻⁶/K.
Official standard thicknesses span 28.60–57.20 mm, suited to thick-walled structural parts.
Short-term temperature resistance up to 500 °C and long-term 450 °C, with HGB 1 / HGA 1 water resistance class.
SUPREMAX® 33 is a rolled borosilicate glass supplied in plate form. Its chemical composition matches SCHOTT BOROFLOAT® 33 and it meets the type 3.3 borosilicate glass described in ISO 3585. The official documentation highlights its low density, low thermal expansion, high thermal resistance, good light transmission and chemical durability.
Plate projects should check sheet thickness tolerances, effective viewing opening, support, sealing, temperature difference, pressure, hole and slot positions and edge condition together. Material parameters cannot replace complete appliance structure, safety factors or application validation.
| Material and standard | Rolled borosilicate glass; borosilicate glass type 3.3 (ISO 3585) |
|---|---|
| Density | 2.23 g/cm³ |
| Young's modulus / shear modulus | 64 / 27 GPa |
| Poisson's ratio | 0.20 |
| Vickers / Knoop hardness | 568（0.2/15）/ 480（0.1/20） |
| Coefficient of thermal expansion (CTE) | 3.25 × 10⁻⁶/K（20–300°C） |
| Specific heat capacity | 0.83 kJ/(kg·K)（20–100°C） |
| Thermal conductivity | 1.2 W/(m·K)（90°C） |
| Softening point / annealing point / strain point | 820°C / 560°C / 518°C |
| Glass transformation temperature Tg | 530°C |
| Refractive index nd | 1.472（587.6 nm） |
| Stress-optical coefficient / dispersion | 4.0 × 10⁻⁶ mm²/N / 71.9 × 10⁻⁴ |
| Dielectric constant / loss tangent | 4.6 / 27 × 10⁻⁴（25°C，1 MHz） |
| Acid / alkali resistance | Class 1 (ISO 1776) / Class A2 (ISO 695) |
| Water resistance class | HGB 1（ISO 719）/ HGA 1（ISO 720） |
| Official temperature statement | Short-term maximum 500 °C; long-term maximum 450 °C |
The official SCHOTT data sheet gives a rough plate size of 1,200 × 1,500 mm and a net size of 1,000 × 1,500 mm.
Thickness tolerance ±1.0 mm
Thickness tolerance ±1.6 mm
Thickness tolerance ±3.2 mm
Thickness tolerance ±6.4 mm
Cut-to-drawing within standard plate sizes can be assessed. Stock, minimum order quantity, sheet condition, finished-part tolerances and lead time must be confirmed in writing before ordering.
The official SCHOTT data sheet gives typical transmission curves over 250–900 nm for thicknesses of 28.60, 31.75, 34.90, 41.30, 47.60 and 57.20 mm.
View the SCHOTT official transmission spectrum PDF ↓
Plate processing requires control of cutting allowance, hole and slot edges, fixturing datums, thermal stress, dimensional accumulation and handling risk.
Precision glass processing services. Precision glass grinding. For borosilicate glass, aluminosilicate glass, …
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We plan the glass cutting route around dimensions, datums, edge condition and downstream operations, reviewing outline, cutting allowance and delivery requirements against the drawing.
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Grinding and polishing operations are arranged around thickness, parallelism, flatness and surface requirements, with the process route and inspection method confirmed per project.
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We control particles, residues and water marks after processing, and confirm cleaning, handling and packaging requirements against coating, bonding or assembly needs.
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Glass dimensions, edges and surfaces are inspected against the drawing and the agreed acceptance items, with inspection methods, sampling scope and delivery records defined.
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We address sharp edges and local edge defects after cutting, confirming edge grinding and chamfer styles and edge acceptance criteria against assembly requirements.
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For micro-holes, hole arrays and local openings in glass, we evaluate laser drilling options based on material, thickness and hole geometry.
View ProcessingStructures involving high temperature, pressure or personal safety must be validated by the appliance or engineering designer.
SCHOTT states that the two have the same chemical composition; SUPREMAX® 33 uses a rolled process and focuses on the ultra-thick range that BOROFLOAT® 33 micro-float cannot provide.
Cutting, drilling, slotting, edge grinding, lapping and polishing can be assessed within standard plate sizes; actual capability depends on thickness, dimensions, tolerances and edge requirements.
No — a material temperature figure cannot replace structural design. The official values are a short-term maximum of 500 °C and long-term 450 °C, and the temperature difference, dimensions, support, load and service life must also be checked.
The official figures are typical curves for a given thickness. Formal acceptance should specify wavelength, thickness, transmission and test method in the quotation and drawing.
Please provide drawings, original material requirements, dimensions, thickness, quantity, temperature, load, holes and slots, edges, surface and acceptance conditions.
Send the drawing, thickness, quantity, operating temperature and key acceptance items, and we will confirm material, processing, inspection and delivery conditions in a single quotation.