What is the difference between BK7 and B270?

Difference Between BK7 and B270 Glass

BK7 and B270 are two types of optical glass used extensively in the manufacturing of lenses, prisms, and other optical components. Despite their similar applications, they have distinct properties and compositions that make them suitable for different optical engineering tasks.

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Composition and Properties

• BK7 is a high-quality borosilicate crown glass. It is well-known for its high purity and excellent optical properties. BK7 has a refractive index of 1. and Abbe number of 64.2, indicating its efficiency in minimizing chromatic aberration.
• B270 is also known as 'Superwite' glass. It is a soda-lime glass that is less expensive to produce compared to borosilicate glasses like BK7. B270 has a slightly higher refractive index of around 1.523 and a lower Abbe number, which means it has a bit more dispersion compared to BK7.

Applications

• BK7 is preferred for high precision optical applications where minimal chromatic aberration is crucial. It is commonly used in the production of high-quality lenses, prisms, and optical windows that require excellent light transmission and stability over a wide range of wavelengths.
• B270 is often chosen for applications where cost is a significant factor, and the optical performance requirements are less stringent. It is widely used in picture framing glass, simple lenses, and windows where high light transmission is needed but without the stringent optical specifications required for high-end optical applications.

Physical and Chemical Durability

BK7 offers superior chemical and physical durability compared to B270. It is more resistant to water and various chemicals, making it suitable for use in harsher environments. BK7 also has a higher melting point, which contributes to its stability in applications involving high temperatures.

B270, on the other hand, is more susceptible to chemical wear and physical damage. Its lower melting point and soda-lime composition make it less ideal for applications that require high durability and resistance to environmental factors.

Conclusion

In summary, the choice between BK7 and B270 depends on the specific requirements of the optical application, including considerations of optical performance, durability, and cost. BK7 is the go-to option for high-precision optical components, while B270 is suitable for less demanding applications where cost-effectiveness is a priority.

Quality is extremely important in industries like optical and display.

Swift Glass offers a wide selection of optical and display glass so you can find the properties and manufacturer that work best for your application. We also supply color filters manufactured by Schott, Kopp and Hoya for photography, color stage lighting and optical instruments.

Our selection of optical glass and display glass includes the following manufacturers and brands:

Schott

• SCHOTT D263® is a thin borosilicate glass with low alkali content produced with extremely pure raw materials making it highly chemical resistant.  It has excellent surface quality that can be coated without any post-process surface work. The combination of these traits makes D263® highly versatile.
• B270® crown glass is suitable for a variety of different market demands ' especially biotech applications.  It offers high chemical stability and high transmittance and has a firepolished surface.
• BK7® glass is an extremely common crown glass used in precision lenses.  BK7 performs well in chemical tests and no special handling is required.

Corning

• Eagle ®: EAGLE ® glass is a lightweight AMLCD Alkaline Earth Boro-Aluminosilicate glass with low density and a low coefficient of thermal expansion.  It features  excellent flatness and  high surface quality that is indispensable for high resolution applications.
• Eagle XG®: Eagle XG®is the industry's first LCD glass to contain no added arsenic, antimony, barium or halides.  It offers low-density, high chemical durability and a pristine surface ideal for high-resolution displays.

Starphire®

Starphire® glass is the ultimate in ultra-clear glass technology.  It contains less than 10 percent of the iron present in conventional glass. Because of this low iron content, Starphire® glass allows more light to pass through it than conventional clear glass.  But what makes Starphire® glass truly unique is its  blue edge.  Unlike conventional glass, which becomes  greener as thicknesses increase, Starphire® glass gains a distinctive blue edge while the surface of the glass remains ultra-clear.

View the table below for a complete list of our optical and glass materials. If you have any questions, feel free to contact us today.

 

Diamant

SGG Diamant transmits up to 92% of visible light, depending on thickness and is a high quality clear float glass with exceptional clarity and high light transmission.

Low Iron Glass

Low-Iron Soda Lime glass provides high light transmission, can be AR coated for super high transmission, can be chemically strengthened, and has good flatness and no green tint.

For more information, please visit N-BK7 Dome.

Mirror

A reflective glass either first or second surface reflectances up t o 94% visible.

Welder's Glass (Weld Glass)

A heat resistant grey-green tinted glass made to provide the correct eye protection for every welding operation. The shade numbers 1-14 refer to the density needed for the different welding operations. The higher the number, the darker the shade.

X-Ray Shielding Glass

X-Ray Shielding Glass is superior to acrylic in radiation protective applications. Compared to acrylic, lead X-Ray glass is much thinner and lighter. Acrylic also can yellow with age and be easily scratched. Glass is available in laminated formats where impact safety is a requirement.

Lead Glass

Lead glass is effective for x-ray shielding and for other forms of radiation shielding due to the attenuation of ionizing photons as a result of lead's high atomic number. Lead Glass is used when a clear view and radiation shielding is of absolute priority in diagnostic, therapy, isotopic or nuclear radiation sources ' used for medical treatment, imaging, testing, inspection, experimentation or energy production.

Radiation Shielding Glass

Lead radiation shielding glass is effective for x-ray shielding and for other forms of radiation shielding due to the attenuation of ionizing photons as a result of lead's high atomic number. Lead Glass is used when a clear view and radiation shielding is of absolute priority in diagnostic, therapy, isotopic or nuclear radiation sources ' used for medical treatment, imaging, testing, inspection, experimentation or energy production.

Color Filters

Optical filters selectively transmit light in a particular range of wavelengths, (colors,) while blocking the remainder. They can usually pass long wavelengths only (longpass), short wavelengths only (shortpass), or a band of wavelengths, blocking both longer and shorter wavelengths (bandpass). The passband may be narrower or wider; the transition or cutoff between maximal and minimal transmission can be sharp or gradual. Optical filters are commonly used in photography (where some special effect filters are occasionally used as well as absorptive filters), in many optical instruments, and to color stage lighting.

View all Materials >>

If you want to learn more, please visit our website Stock Optical Domes factory.