Mechanical resistance

When using glass, please avoid thermal stresses (e.g. open flames in the transformation temperature range), thermal shocks and damages on the surface as heavy scratches or cracks. This can lead to breakage of the glass and thus can cause injuries.

Printing colours, graduation

The graduation of the glass instruments is usually applied with screen printing method. Therefor we are using two different types of graduation colours: Enamel colours are melting with the glass surface at the particular burn-in temperature. This long-lasting burnt-in colour has sufficient resistance for the daily use and has due to the rich contrasts a very good readability.

Diffusion colour diffuses through ion exchange into the glass surface and is practically indestructible and even longer-lasting than enamel colours. This colour is also suitable for very demanding applications. The intense brown colouring also assures an excellent readability.


Laboratory glassware can be cleaned manually or mechanically. It is to be paid attention that particularly on volumetric instruments (e.g. graduations) and at articles with application-specific printings (e.g. filling marks) the temperature of the rinsing bath is not > 70°C when alkaline detergents are used. Furthermore the exposure time in the rinsing bath should be kept to a minimum. Alkaline media in connection with temperatures > 50°C and longer exposure time can lead to changes in the volume by glass erosion and destruction of the graduation. You should never use abrasive detergents, as these may cause damages in the glass surface und thus can impair the use of the glass instruments. Our recommendation for cleaning is to use water > 90°C without chemical additives (hot water cleaning). At glass instruments made of soda lime glass, abrupt changes in temperature are to be avoided.

Technical information

Borosilicate glass 3.3

Borosilicate glass 3.3 is made according to DIN ISO 3585:1998 and meets the following chemical properties:

  • hydrolytic resistance class 1 (DIN ISO 719)
  • acid resistance class 1 (DIN 12116)
  • alkaline solution resistance class 2 (DIN ISO 695)
  • coefficient of mean linear thermal expansion α (20°C-300°C) acc. to DIN ISO 7991 = 3.3 * 10-6K-1


Furthermore borosilicate glass 3.3 has very good physical properties, e.g. very high thermal resistance and thermal shock resistance. The maximum short-time working temperature is  500°C. Therefore all our products made of borosilicate glass 3.3 are universally applicable in laboratories and industry.


Soda-lime glass

Soda-lime glass has the following chemical properties:

  • hydrolytic resistance class HGB 3 (DIN ISO 719)
  • acid resistance class S 1 (DIN 12116)
  • alkaline solution resistance class A 2 (DIN ISO 695)
  • coefficient of mean linear thermal expansion α (20°C-300°C) acc. to DIN ISO 7991 = 9.1*10-6K-1


Articles made of soda-lime glass (e.g. graduated and volumetric pipettes) are used in laboratories  for applications with less thermal requirements.