H-PZ33 Low Expansion Glass
H-PZ33 is a low expansion borosilicate glass characterized by high light transmittance, excellent thermal stability, excellent mechanical hardness, and excellent chemical durability. H-PZ33 has become the glass of choice for MR11 reflectors, MR16 reflectors, UHP lamps, parabolic aluminized reflectors, telescope mirrors, and any application where a low coefficient of thermal expansion is called for.
| H-PZ33 Physiochemical Properties |
| Refractive index (nd) |
1.47200 |
| Dispersion (nF- nC) |
0.00719 |
| Coefficient of Linear thermal expansion (x10-6/°C) |
3.25 |
| Thermal conductivity (W/(m * °C)) |
1.14 |
| Average thermal capacity (KJ/ (kg * °C)) |
0.83 |
Maximal operation temperature (°C)
Short Term
Long Term
Thermal stability |
500
450
375 |
| Density (g/cm3) |
2.23 |
| Elastic modulus E (kN/mm3) |
64 |
| Hardness (HK) |
480 |
| Poission's Ratio |
0.2 |
| Climatic resistance (ISO - 719 - HGB) |
Grade 1 |
| Acid resistance |
Grade 1 |
| Alkali resistance |
Grade 1 |
| Melting temperature (°C) |
1680 |
| Working Point (°C) |
1252 |
| Softening Point (°C) |
820 ± 10 |
| Annealing Point (°C) |
560 ± 10 |
| Stress Point (°C) |
510 ± 10 |
| Surface Tension (dyn/cm) |
340-350 (1252 °C) |
| Dielectric constant (1MHz, 20°C) |
4.6 |
| Dielectric loss (1MHz, 20°C) |
37 x 10-4 |
| Dielectric strength (50MHz, 25°C) Kv/mm |
16 |
| Color Code (λ5/λ80) |
297.6/337.2 |
Volume Sensitivity (log ρ)
250°C
350°C |
8.0
6.5 |
| Environmental Protection |
Pb < 50 ppm
As < 5 ppm
Cd < 5 ppm
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