Volumetric flasks, also called graduated flasks or measuring flasks, are items of laboratory glassware or plasticware calibrated and labelled to contain a specified volume of reagents, solvents, or other liquids.

Volumetric flasks are often used to create chemical solutions. Many are manufactured and calibrated in ISO/IEC-certified laboratories and meet different ASTM and ISO standards of quality and dependability.

Volumetric flasks are typically pear shaped, with a flat base and long neck. They typically feature a single graduation ring etched or marked on the neck to define the specified fill level. They may also be supplied with a glass or plastic stopper.

Volumetric flasks come in capacities from 1 mL to 4 L and may be manufactured from either glass (borosilicate or soda lime) or autoclavable and chemical-resistant plastics such as polymethylpentene, polypropylene, or PFA. Glass versions may be clear, colored, or coated for handling light-sensitive liquids. Plastic flasks offer the advantage of being break-resistant and may also offer lower extractable profiles.

A Kohlrausch volumetric flask is modified to help transfer large amounts of solids into the flask for dissolution; it is commonly used to measure the sugar content of sugar beets. A Le Chatelier flask is designed for specific gravity determinations.

What Is the Difference Between Class A and B Volumetric Flasks?
Class A flasks are manufactured to high standards of precision for critical analytical work (often with a unique serial number for traceability), whereas Class B flasks offer less accuracy and are therefore more suitable for less demanding applications such as qualitative or educational use. Volumetric flasks are important items in a range of laboratory environments in both research and industry.

What Are Typical Applications of Volumetric Flasks?
• Preparation of standard solutions
• Preparation of series dilutions
• Filling, measuring, and decanting precise volumes of liquid
• Calibrating other containers and devices