B270 Optical Glass
| Thermal Properties | |
| Thermal Coefficient of Expansion | (0/300°C): 95 X 10 -7/°C |
| Annealing Point | 541°C / 1006 °F |
| Softening Point | 724°C / 1335 °F |
| Strain Point | 511°C / 952 °F |
| Mechanical Properties | |
| Density | 2.55 g/cm3 |
| Knoop Hardness | 542 |
| Young's Modulus | E=71.5 kN/mm2 |
| Poisson's Ratio | .219 |
| Optical Properties | |
| Refractive Index | 1.5230 |
| Chemical Properties | |
| Hydrolytic Resistance | class 3 |
| Acid Resistance | class 2 |
| Alkali Resistance | class 2 |
| Electrical Properties | |
| Dielectric Constant | E=7 |