Glassco Round Bottom Flask — Single Neck with NS Ground Glass Joint
The Glassco round bottom flask with single neck and NS ground glass joint is a high-quality borosilicate 3.3 glass flask manufactured to DIN/ISO 4797 and USP standards. The spherical round bottom design distributes heat uniformly across the flask surface and provides structural strength under vacuum conditions — making these flasks the standard choice for heating mantle applications, rotary evaporator use, vacuum distillation, and reflux setups in pharmaceutical, research, and analytical laboratory environments.
Available in capacities from 25mL to 2000mL with NS 14/23 and NS 29/32 ground glass neck joints, these round bottom flasks are supplied from Glassco’s European warehouse in the Netherlands for fast and reliable delivery across Ireland.
Key Features
DIN/ISO 4797 and USP Compliant
Manufactured in compliance with DIN/ISO 4797 and USP standards, ensuring consistent dimensional accuracy, wall thickness, and material quality across all sizes. Compliance with these internationally recognised standards supports their use in regulated pharmaceutical and research laboratory environments.
NS Ground Glass Joint
The NS (Normalschliff) standard taper ground glass joint provides a reliable, leakproof connection to standard laboratory glassware fittings, condensers, adaptors, and distillation equipment — ensuring compatibility with all standard laboratory setups. NS 14/23 is available on smaller sizes and NS 29/32 on larger capacities.
Borosilicate 3.3 Glass
Manufactured from borosilicate 3.3 glass, providing excellent chemical resistance to acids, bases, and organic solvents, along with good thermal shock resistance for heating and vacuum applications.
Uniform Wall Thickness
Uniform wall thickness ensures consistent heat distribution during heating mantle use and structural integrity under vacuum — reducing the risk of cracking or implosion during demanding laboratory procedures.
White Printing
Clear white printing provides durable capacity marking and laboratory identification on the flask surface, resistant to normal laboratory cleaning and handling conditions.
Technical Specifications
| Parameter | Specification |
|---|---|
| Brand | Glassco |
| Type | Round Bottom Flask, Single Neck |
| Glass Type | Borosilicate 3.3 |
| Standard Compliance | DIN/ISO 4797, USP |
| Neck Type | NS Ground glass standard taper joint |
| Printing | White |
| Available Capacities | 25mL, 50mL, 100mL, 250mL, 500mL, 1000mL, 2000mL |
| Supply Origin | Glassco European Warehouse, Netherlands |
Capacity, NS Joint and Stock Reference
| Capacity | NS Joint | OD × H (mm) | Item Code |
|---|---|---|---|
| 25mL | NS 14/23 | 41 × 85 | EU057.202.05 |
| 50mL | NS 14/23 | 51 × — | EU057.202.08 |
| 50mL | NS 29/32 | 51 × 105 | EU057.202.10A |
| 100mL | NS 14/23 | 64 × 115 | EU057.202.11 |
| 100mL | NS 29/32 | 64 × 115 | EU057.202.14 |
| 250mL | NS 29/32 | 85 × 145 | EU057.202.23 |
| 500mL | NS 29/32 | 105 × 175 | EU057.202.27 |
| 1000mL | NS 29/32 | 131 × 210 | EU057.202.31 |
| 2000mL | NS 29/32 | — | EU057.202.34 |
Applications
- Rotary evaporation — standard flask format for rotary evaporator solvent removal in pharmaceutical synthesis and sample concentration
- Heating mantle use — uniform heat distribution for reflux, distillation, and chemical reaction applications
- Vacuum distillation — structural strength under vacuum conditions for distillation and concentration workflows
- Reflux assemblies — connection to condensers and distillation setups via NS ground glass joint
- Pharmaceutical research and synthesis — general reaction vessel for laboratory-scale synthesis and preparation workflows
Availability in Ireland
Available from Varen Scientific — Ireland’s authorised distributor for Glassco laboratory glassware, supplied from the European warehouse in the Netherlands. For further information on borosilicate glass standards, refer to ISO laboratory glassware guidance. To request a quote, use the Request a Quote button above or contact our team directly.






