PBM25 by Ohara

Obsolete Unknown Environmentally Dangerous

PBM25 by Ohara is an obsolete optical glass. It transmits from 0.33 to 0.90 µm with an nd of 1.6727 and a Vd of 32.101636. It has medium thermal expansion (CTE of 8.5×10⁻⁶/K), good chemical resistance, and dangerous environmental properties.

Refractive Index vs Wavelength
Refractive Index Calculator
Valid range: 0.3–2.4 µm
dn/dλ vs Wavelength
dn/dλ Calculator
Valid range: 0.3–2.4 µm
Abbe Number Calculator
Transmission vs Wavelength
Transmission Calculator
Valid wavelength range: 0.330–0.900 µm
Optical Properties
Refractive Index (nd) 1.6727
Abbe Number (Vd) 32.101636
Dispersion Formula Schott
Wavelength Range 0.3 — 2.4 µm
$$n(\lambda) = \sqrt{2.71076 - 0.00928892\,\lambda^2 + 0.0275423\,\lambda^{-2} + 0.00135126\,\lambda^{-4} - 5.45639 \times 10^{-5}\,\lambda^{-6} + 8.32611 \times 10^{-6}\,\lambda^{-8}}$$
Thermal Properties
TCE -30/70°C (10-6/K) 8.5
TCE 100/300°C (10-6/K) 9.5
Thermal Conductivity (W/mK) —
Heat Capacity (J/gK) —
$$\frac{dn}{dT} = \frac{n_0^2 - 1}{2\,n_0}\left[6.818 \times 10^{-6} + 2(0)\,\Delta T + 3(0)\,\Delta T^2 + \frac{0 + 2(0)\,\Delta T}{\lambda - 0}\right] \Delta T = T - T_0, \quad T_0 = 25\,°\text{C}$$
Physical Properties
Density (g/cm³) 4.07
Relative Cost —
Mechanical Properties
Young's Modulus (GPa) —
Poisson's Ratio —
Knoop Hardness (kgf/mm²) —
Chemical Resistance
Climatic Resistance —
Stain Resistance —
Acid Resistance 2
Alkali Resistance —
Phosphate Resistance 2
Similar Glasses (Other Manufacturers)
Glass Manufacturer nd Vd Compare
E-FD5 Hoya 1.6727 32.17
H-ZF2 CDGM 1.6727 32.171186
FD5 Hoya 1.672701 32.173263
ZF2 CDGM 1.672707 32.180986
SF5 Sumita 1.6727 32.2
SF5 Schott 1.6727 32.21
N-SF5 Schott 1.67271 32.25
C72-32 Corning 1.672698 32.31788
SF19 Schott 1.6668 33.005581
H-ZF39 CDGM 1.6668 33.053728
Similar Glasses (Ohara)
Glass Manufacturer nd Vd Compare
S-TIM25 Ohara 1.6727 32.099206
PBM39 Ohara 1.666799 33.046816
S-TIM39 Ohara 1.6668 33.054985
PBM28 Ohara 1.68893 31.082901
PBM28W Ohara 1.68893 31.082901
S-TIM28 Ohara 1.688931 31.07545
L-TIM28 Ohara 1.689479 31.023399
L-TIM28P Ohara 1.694529 30.655992
S-TIM22 Ohara 1.647689 33.792803
PBM22 Ohara 1.647689 33.802937
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