round flasks

Round bottom flask with narrow or wide neck made of borosilicate glass 3.3.

Round bottom flask made of borosilicate glass 3.3

  • Temperature resistant up to +250 °C
  • Resistant to acids, alcohols and chemicals, except hydrofluoric acid and concentrated alkaline solutions
  • Can be autoclaved and sterilised
  • dishwasher-safe

Borosilicate glass has high thermal and chemical stability. The surface is smooth and non-porous, inert and corrosion-resistant. It is widely used in laboratory glassware, industrial equipment and domestic cooking glassware.

In the Laboratory

  • Uniform heating of contents
  • Suitable for use under vacuum

Multi-neck Flask

  • Destillation
  • Extraktion
  • Synthese

Appropriate Use of the Round-bottom Flask

  • In physics lessons to demonstrate the cobbler's ball (see also "Useful information")

Round-bottom flasks have a spherical body and a cylindrical neck. A tripod or laboratory stand is required for stability. The round shape allows for even heating of the contents. Unlike Erlenmeyer and vertical flasks, round-bottom flasks can safely be used under vacuum without risk of implosion.
Multi-neck flasks, which are a type of round-bottom flask, come with two, three, or more openings featuring ground joint sleeves. These openings allow simultaneous connection to a condenser, stirrer, measuring devices, or feeds, making them useful for processes like distillation, extraction, and synthesis.
Flasks can be cleaned manually in an immersion bath or mechanically in a dishwasher.


The Cobbler's Ball Explained:
A round-bottom flask can also be used as a cobbler's ball. To do this, fill the narrow-necked round-bottom flask with water and seal it with a cork stopper.
Before the advent of electric light, cobblers used this tool to focus the diffuse light from the sun, gas, or oil lamps, thereby illuminating their workspace on dimly lit days. The cobbler's ball also filtered heat radiation from the light source, enabling work with temperature-sensitive materials near a strong light source.

Material
Neck shape
Volume

8ZC-50-2750

Round-Bottom Flask 50 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
50 ml
Neck opening
26 mm
Diameter
51 mm
Height
95 mm

starting from CHF 11.35

8ZC-50-2751

Round-Bottom Flask 100 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
100 ml
Neck opening
26 mm
Diameter
64 mm
Height
110 mm

starting from CHF 11.89

8ZC-50-2766

Wide Neck Round-Bottom Flask 100 ml

These flasks from DURAN, made from high-quality borosilicate glass 3.3, are characterized by excellent temperature resistance up to 250°C. The round-bottom design also provides resistance to acids, alcohols, and various chemicals, highlighting their versatility and applicability in the laboratory.
Material
DURAN clear glass
Volume
100 ml
Neck opening
35 mm
Diameter
64 mm
Height
110 mm

starting from CHF 12.97

8ZC-50-2752

Round-Bottom Flask 250 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
250 ml
Neck opening
34 mm
Diameter
85 mm
Height
144 mm

starting from CHF 14.05

8ZC-50-2767

Wide Neck Round-Bottom Flask 250 ml

These flasks from DURAN, made from high-quality borosilicate glass 3.3, are characterized by excellent temperature resistance up to 250°C. The round-bottom design also provides resistance to acids, alcohols, and various chemicals, highlighting their versatility and applicability in the laboratory.
Material
DURAN clear glass
Volume
250 ml
Neck opening
51 mm
Diameter
85 mm
Height
143 mm

starting from CHF 16.22

8ZC-50-2753

Round-Bottom Flask 500 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
500 ml
Neck opening
34 mm
Diameter
105 mm
Height
168 mm

starting from CHF 18.38

8ZC-50-2768

Wide Neck Round-Bottom Flask 500 ml

These flasks from DURAN, made from high-quality borosilicate glass 3.3, are characterized by excellent temperature resistance up to 250°C. The round-bottom design also provides resistance to acids, alcohols, and various chemicals, highlighting their versatility and applicability in the laboratory.
Material
DURAN clear glass
Volume
500 ml
Neck opening
50 mm
Diameter
105 mm
Height
168 mm

starting from CHF 32.43

8ZC-50-2754

Round-Bottom Flask 1000 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
1000 ml
Neck opening
42 mm
Diameter
131 mm
Height
200 mm

starting from CHF 34.59

8ZC-50-2769

Wide Neck Round-Bottom Flask 1000 ml

These flasks from DURAN, made from high-quality borosilicate glass 3.3, are characterized by excellent temperature resistance up to 250°C. The round-bottom design also provides resistance to acids, alcohols, and various chemicals, highlighting their versatility and applicability in the laboratory.
Material
DURAN clear glass
Volume
1000 ml
Neck opening
50 mm
Diameter
131 mm
Height
200 mm

starting from CHF 30.27

8ZC-50-2755

Round-Bottom Flask 2000 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
2000 ml
Neck opening
42 mm
Diameter
166 mm
Height
260 mm

starting from CHF 61.62

8ZC-50-2770

Wide Neck Round-Bottom Flask 2000 ml

These flasks from DURAN, made from high-quality borosilicate glass 3.3, are characterized by excellent temperature resistance up to 250°C. The round-bottom design also provides resistance to acids, alcohols, and various chemicals, highlighting their versatility and applicability in the laboratory.
Material
DURAN clear glass
Volume
2000 ml
Neck opening
76 mm
Diameter
165 mm
Height
240 mm

starting from CHF 59.46

8ZC-50-2756

Round-Bottom Flask 3000 ml

Round-bottom flask with a narrow neck made of clear DURAN glass, ideal for precise laboratory experiments. Its round shape enables uniform heating, making it the perfect choice for a wide range of laboratory applications.
Material
DURAN clear glass
Volume
3000 ml
Neck opening
50 mm
Diameter
185 mm
Height
260 mm

starting from CHF 94.05