K-SK4 by Sumita
Standard
Rare
Environmentally Friendly
K-SK4 by Sumita is a standard optical glass with a rare melt frequency. It transmits from 0.28 to 2.00 µm with an nd of 1.61272 and a Vd of 58.6. It has low thermal expansion (CTE of 6.1×10⁻⁶/K) and below average chemical resistance.
Refractive Index vs Wavelength
Refractive Index Calculator
dn/dλ vs Wavelength
dn/dλ Calculator
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Optical Properties
Thermal Properties
| TCE -30/70°C (10-6/K) | 6.1 |
|---|---|
| TCE 100/300°C (10-6/K) | 7.6 |
| Thermal Conductivity (W/mK) | — |
| Heat Capacity (J/gK) | — |
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[4.04 \times 10^{-7} + 2(1.86 \times 10^{-8})\,\Delta T + 3(-3.68 \times 10^{-10})\,\Delta T^2 + \frac{4.13 \times 10^{-7} + 2(4.69 \times 10^{-10})\,\Delta T}{\lambda - 0.197}\right]
\Delta T = T - T_0, \quad T_0 = 20\,°\text{C}$$
Chemical Resistance
| Climatic Resistance | 3 |
|---|---|
| Stain Resistance | — |
| Acid Resistance | 4 |
| Alkali Resistance | — |
| Phosphate Resistance | — |
Similar Glasses (Other Manufacturers)
| Glass | Manufacturer | nd | Vd | Compare |
|---|---|---|---|---|
| BACD4 | Hoya | 1.61272 | 58.58 | |
| H-ZK6 | CDGM | 1.61272 | 58.577083 | |
| SK4 | Schott | 1.61272 | 58.629829 | |
| C13-58 | Corning | 1.612693 | 58.570371 | |
| N-SK4 | Schott | 1.61272 | 58.63 | |
| S-BSM4 | Ohara | 1.612716 | 58.716945 | |
| BSM4 | Ohara | 1.612716 | 58.749129 | |
| H-ZK4 | CDGM | 1.60881 | 58.855991 | |
| BACD3 | Hoya | 1.608812 | 58.863994 | |
| SK3 | Schott | 1.60881 | 58.921505 |