BK8 by Schott

Obsolete Unknown Environmentally Dangerous

BK8 by Schott is an obsolete optical glass. It transmits from 0.33 to 2.33 µm with an nd of 1.520152 and a Vd of 63.685744. It has medium thermal expansion (CTE of 7.4×10⁻⁶/K) and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.334–2.325 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.334–2.325 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.334–2.325 µm
Optical Properties
Refractive Index (nd) 1.520152
Abbe Number (Vd) 63.685744
Dispersion Formula Sellmeier
Wavelength Range 0.334 — 2.325 µm
$$n(\lambda) = \sqrt{1 + \frac{1.05499\,\lambda^2}{\lambda^2 - 0.00620952} + \frac{0.225825\,\lambda^2}{\lambda^2 - 0.0201593} + \frac{1.00519\,\lambda^2}{\lambda^2 - 106.22}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 7.4
TCE 100/300°C (10-6/K) 8.7
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[1.33 \times 10^{-6} + 2(1.28 \times 10^{-8})\,\Delta T + 3(-8.27 \times 10^{-11})\,\Delta T^2 + \frac{2.89 \times 10^{-7} + 2(3.34 \times 10^{-10})\,\Delta T}{\lambda - 0.267}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 2.57
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance —
Stain Resistance —
Acid Resistance —
Alkali Resistance —
Phosphate Resistance —
Notes

old

Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
P-BK40 Sumita 1.5176 63.5
K-PBK40 Sumita 1.5176 63.5
D-K59 CDGM 1.5176 63.499991
H-K90GTI CDGM 1.51948 63.291634
D-K59-25 CDGM 1.51698 63.4085
S-BSL7R Ohara 1.51633 63.881689
D-K9 CDGM 1.51633 64.058952
D-K9GT CDGM 1.51633 64.058952
L-BSL7 Ohara 1.51633 64.065129
K-BK7 Sumita 1.51633 64.1
Similar Glasses (Schott)
Glass Manufacturer nd Vd Compare
BK7G18 Schott 1.51975 63.58
P-BK7 Schott 1.5164 64.06
BK7 Schott 1.5168 64.167336
N-BK7HT Schott 1.5168 64.17
N-BK7HTSultra Schott 1.5168 64.17
N-BK7HTi Schott 1.5168 64.17
N-BK7 Schott 1.5168 64.17
BK7HT Schott 1.51633 64.14348
UBK7 Schott 1.516801 64.289727
PK3 Schott 1.525419 64.662422
Compare Glasses
    Compare Selected