Schlenk flask

The Schlenk flask is a special form of laboratory flask used primarily in connection with the so-called Schlenk technique.
This chemical working method, developed by the German chemist Wilhelm Schlenk (1879 to 1943), is used to handle substances that are sensitive to air or moisture using a vacuum or inert gases such as nitrogen and argon. However, it is also suitable for the safe handling of highly volatile, toxic media.
Schlenk flasks are pear-shaped and round and, in addition to a ground joint, have a side arm with a valve. This allows the flask to be connected to an inert gas vacuum system, via which it can be vented and charged with inert gas.
In addition, the vessels can be used in conjunction with a so-called Schlenk frit. This laboratory device, also known as a reverse frit, was specially designed to separate air- or water-sensitive suspensions into liquid and solid under inert gas conditions.

Our Schlenk flasks

Features of our flasks

The possible applications of Schlenk flasks in the laboratory are extremely diverse. In order to meet the different requirements of the various fields of application, we manufacture the vessels according to customer specifications. This means: You can freely select the nominal volume (the contents), as well as define ground joints and valves according to your needs. The following valves are available for selection:

  • NS glass tap,
  • NS cock with PTFE plug,
  • PRODURAN high vacuum spindle valve and
  • YOUNG high vacuum spindle valve.

Customized special design

All Schlenk apparatuses and vessels, we manufacture exclusively according to customer requirements. If you already have exact ideas of your product, you can send them to us via our inquiry form. Simply upload a drawing or a PDF sketch or describe what you need. We will be happy to provide you with an individual offer.

Would you like detailed advice? Then simply get in touch with a contact person of your choice and make an appointment. We would be happy to visit you on site to find out in detail about your requirements and to make appropriate proposals.

FAQs on the subject of Schlenk flasks

How well does the inert layer protect the contents when the flask is opened?

The space between the bottom of the flask and the gas inlet is relatively narrow, which means that the inert gas cushion over the air- and water-sensitive substance is not very thick. When working on the open flask, there should therefore always be a slight protective gas flow to reliably prevent the inflow of air.

What material are used for Schmizo Schlenk flasks?

We manufacture the flasks from borosilicate glass. This is characterized by very good chemical and temperature resistance and is therefore ideally suited for use in the laboratory. The maximum working temperature of this material is 500 °C, the glass transition temperature 525 °C.

Borosilicate glass is inert to most chemicals. However, it is attacked under permanent exposure to hydrofluoric acid, concentrated alkalis such as sodium hydroxide solution or concentrated hot phosphoric acid.

What are the alternatives to the flask?

Alternatively, you can use a Schlenk tube. This is significantly higher and slimmer than the flask and is only rounded at the bottom. Thanks to the elongated design, it is possible to cover air- or water-sensitive media inside with a high inert gas column. Thus, even with the flask open, there is no risk of oxygen or moisture ingress.


Beschreiben Sie Ihre Anforderungen oder laden Sie eine Skizze hoch – wir melden uns in Kürze mit einer individuellen Offerte.

Sascha Ruch
Sacha Ruch

Schmizo AG


    Describe your requirements or upload a sketch – we will get back to you shortly with a customized quote.

    Sascha Ruch
    Sacha Ruch

    Sales manager
    Schmizo AG