Sight glass tubes of borosilicate glass:

We supply round sight glass tubes standard made from 3.3 borosilicate glass. These tubes are resistant to many mediums, high temperatures (continuous temperature 525°C) and pressure.


Outside diameter of Ø 3 ± 0.13 mm up to Ø 465 ± 6 mm.

Wall thickness of 0.7 ± 0.03 mm to 10 ± 1.4 mm.

Click on this PDF-file for all possible dimensions, wall thicknesses and tolerances.


Cutting, beveling, grinding, sizing, flame polishing, drilling, reel off, printing, matting etc.

Other Materials:

We provide other glass tubes sizes and materials (e.g. quartz glass, acrylic glass, plexiglass) on request. For instance: higher pressure, temperature and specific requirements for optical measurements. See Technical glass. Many people prefer plexiglass tubes on their assumption that glass tubes may break quickly. However, borosilicate glass, is a hard type of durable glass. Plexiglass tubes are not resistant to all mediums; the maximum temperature is up to 70 – 90° C. Plexiglass obsoletes eventually (crackle). So we recommend borosilicate glass.

Suitable for the following mediums:

Borosilicate glass tubes are high resistant to water, neutral and acid solutions, concentrated acids and acid mixtures, as well as chlorine, bromine, iodine and organic substances. The following mediums damage the glass surface (depending on the concentration and temperature): hydrofluoric acid, hot phosphoric acid and alkaline solutions. Therefore, with these chemicals the use of borosilicate glass needs to be checked in each individual case.

Size tolerances:

Tolerances depend on the outside diameter and the wall thickness.

Chemical properties:

  • Hydrolytic Class
  • Acid Class
  • Alkali Class
  • (DIN ISO 719) HGB 1.
  • (DIN 12116) Class S 1.
  • (DIN ISO 695) Class A 2.