Continental Trade Sp. z o. o.

Technical glass


Borosilicate rods
Diameter Weight of
1 piece
[mm] [g]   [kg]
3 ± 0,13 24 529 12,5
4 ± 0,13 42 298 12,5
5 ± 0,13 66 183 12,0
6 ± 0,13 95 140 13,2
7 ± 0,13 129 98 12,6
8 ± 0,18 168 80 13,4
9 ± 0,18 213 63 13,4
10 ± 0,18 263 45 11,8
12 ± 0,18 378 35 13,2
14 ± 0,26 515 24 12,4
16 ± 0,26 672 20 13,4
18 ± 0,36 851 20 17,0
20 ± 0,36 1 050 16 16,8
22 ± 0,40 1 271 12 15,3
24 ± 0,40 1 512 12 18,2
26 ± 0,50 1 775 9 16,0
28 ± 0,70 2 059 9 18,5
30 ± 0,70 2 363 6 14,2

Above data refer to DURAN borosilicate rods.

NOTE! The above mentioned borosilicate rods are sold in standard lengths of 1 500 mm.  However, on customer request we can prepare rods of different lengths.

If you can't find correct size - contact us.

Below were reminded properties of DURAN glass described on page Borosilicate glass in section Our offer/Technical glass /Types of materials

DURAN® - DIN 7080

It is a glass highly resistant to water, neutral and acidic environment, solutions and concentrated acid and alkalies, chlorine, bromine, iodine and organic substances. The chemical resistance of the glass Duran® resistance is higher than most metals, even during a prolonged period and at higher temperatures (> 100 ° C). Only hydrofluoric acid, concentrated phosphoric acid, and strong alkaline materials may cause   decrease the surface of glass (glass corrosion) of temperature above 100 ° C.

Maximum working temperature of glass DURAN® is 500 °C. At temperatures above 525 ° C, glass begins to soften, and a temperature above 860 ° C liquefies. May be cooled to a very low freezing temperatures and is therefore suitable for use in contact with liquid nitrogen (about -196 ° C). In general DURAN® products are recommended for use down to - 70 °C, while defrosting must be ensured that the temperature difference does not exceed 100 K.

DURAN® glassware is suitable for use in microwaves.

DURAN® glass is highly resistant to changes of temperature  (ΔT = 100 K). Thanks to the very low coefficient of linear expansion (3.3 x 10-6 1/K) in the articles of this material in practice there are no stresses during rapid temperature changes (e.g. not crack the vessel when filled with boiling water).

DURAN ® is a commercial version 3.3 borosilicate glass, hence the majority of the properties and composition is similar to the type of glass.


SiO2  81% Composition of DURAN
B2O3  13 %
Na2O + K2O 4 %
Al2O3  2%



Density (@ 25 °C) 2.23 g/cm3
Modulus of elasticity (Young’s) 63 * 103 N/mm2
Poisson’s ratio 0.2
Coefficient of linear expansion 3.3 * 10 -6 °C
Thermal conductivity 1.2 W/(m K)
Transformation temperature T(ISO 7884-8) 525 °C
Glass temperature for density dPa s 1013     560 °C  (annealing point)
10 7.6    825 °C  (softening poin)
10 4    1250 °C  (working point)
Thermal shock Δ 100 °C
Index of refraction (@ 380 - 780 nm) 1.474 
Working temperature (maximum):
 - long term 300 °C 
 - temporary (< 10 minutes) 500 °C

Log of the electric volume resistivity:    
- at 250°C
- at 350°C


Chemical resistance

Due to the high content of silica (SiO2), DURAN glass is very resistant to water, acids, organic solvents and halogens. Only hydrofluoric acid, hot concentrated phosphoric acid and strong alkaline solutions cause significant corrosion of the glass. 

Hydrolytic resistance

   Acc.   ISO 719 (@ 98 °C): class HGB 1 
   Acc.   ISO 720 (@ 121 °C): class HGA 1 

Alkali resistance
   Acc. DIN 52 322 (acc.  ISO 695): class A2

Acid resistance
   Acc. DIN 12 116 (ISO 1776): class 1

Dielectric properties

@ 25° C and 1 MHz: 
    Dielectric constant εr=4.6 
    Dielectric loss factor    tan δ= 37*10-4


Optical properties

Spectral Transmission
Spectral Transmission DURAN

DURAN® glass is generally available in the form of tubes, rods, capillaries or laboratory glassware and apparatus. 

While every attempt has been made to verify the source of the information, no responsibility is accepted for accuracy of data.

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