SK18 by Sumita

Obsolete Very Rare Environmentally Dangerous

SK18 by Sumita is an obsolete optical glass with a very rare melt frequency. It transmits from 0.33 to 2.00 µm with an nd of 1.63854 and a Vd of 55.5. It has below average chemical resistance and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.27–2.0 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.27–2.0 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.330–2.000 µm
Optical Properties
Refractive Index (nd) 1.63854
Abbe Number (Vd) 55.5
Dispersion Formula Schott
Wavelength Range 0.27 — 2.0 µm
$$n(\lambda) = \sqrt{2.63842 - 0.0108276\,\lambda^2 + 0.0160588\,\lambda^{-2} + 0.000501226\,\lambda^{-4} - 3.06877 \times 10^{-5}\,\lambda^{-6} + 2.25464 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) —
TCE 100/300°C (10-6/K) 8.1
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[0 + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Physical Properties
Density (g/cm³) 3.69
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance 2
Stain Resistance —
Acid Resistance 5
Alkali Resistance —
Phosphate Resistance —
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
C39-56 Corning 1.638505 55.504447
BACD18 Hoya 1.63854 55.45
H-ZK11 CDGM 1.63854 55.446553
N-SK18 Schott 1.63854 55.423596
SK18A Schott 1.63854 55.423596
BSM18 Ohara 1.638539 55.384768
S-BSM18 Ohara 1.638539 55.380028
M-PCD55AR Hoya 1.63858 55.18
MP-PCD55AR Hoya 1.63858 55.18
LACL1 Hoya 1.640851 56.835319
Similar Glasses (Sumita)
Glass Manufacturer nd Vd Compare
K-SK18RH Sumita 1.63854 55.5
K-SK18 Sumita 1.63854 55.5
SK18RH Sumita 1.63854 55.5
LAKN13 Sumita 1.641 56.8
K-LaKn5 Sumita 1.65 55.8
LAKN5 Sumita 1.65 55.8
SK10 Sumita 1.6228 56.9
LAK6 Sumita 1.6425 58.1
K-LaK6 Sumita 1.6425 58.1
SSKN1 Sumita 1.6485 53.0
Compare Glasses
    Compare Selected