Laboratory Glass Stirring Rods

Choose borosilicate glass 3.3 stirring rods for all laboratory use. Resistant to thermal shock, most acids, bases, and organic solvents, and can be autoclaved or immersion-cleaned. All SmartLabs stirring rods are made from borosilicate glass.

Standard stirring rods are 5 to 6 mm in diameter for general bench work. Thinner 3 mm rods suit narrow vessels such as test tubes. Thicker 7 to 8 mm rods provide more rigidity for dense or viscous solutions. Match the rod diameter to the opening of the vessel you are working with.

Select a rod at least 10 to 15 cm longer than the depth of the vessel so you can grip it without touching the rim or contents. Common lengths range from 150 mm for small beakers to 300 to 400 mm for larger preparation vessels.

A rubber policeman is a rubber or silicone cap fitted to the end of a stirring rod that scrapes solid residues from glassware walls during transfers and gravimetric analysis. Select a rod diameter that fits a compatible rubber policeman if complete quantitative transfer is required.

Glass stirring rods are used to manually mix liquids, dissolve solids, break up precipitates, direct liquid flow when pouring, coat surfaces with thin layers of solution, and apply pressure to transfer solids. They are a core hand tool in chemistry, biology, and general science laboratories.

A 5 to 6 mm diameter rod is the standard choice. It is strong enough to break up precipitates, compatible with most rubber policeman attachments, and fits a wide range of beakers and flasks. Thinner 3 mm rods suit narrow vessels; thicker 7 to 8 mm rods suit heavy stirring tasks.

Borosilicate glass stirring rods are resistant to most laboratory chemicals including dilute and concentrated acids (except hydrofluoric acid), bases, and organic solvents. For hydrofluoric acid, use PTFE stirring rods. Strongly alkaline solutions at elevated temperatures can gradually etch glass over repeated exposures.

Borosilicate glass stirring rods can be used in heated solutions and autoclaved at 121 degrees Celsius. Do not heat a cold rod in a direct flame or plunge it into very hot liquid without pre-warming. Allow rods to cool before handling after use in hot solutions.

A rubber policeman is a rubber or silicone cap that fits onto the end of a stirring rod, providing a soft tip that scrapes solid residues from glassware without scratching. Used in gravimetric analysis and quantitative precipitate transfers where complete removal of solid material is required. Select one that fits snugly on your rod diameter.