Materials Used in Magnetic Stir Bars

What Is Indispensable to a Magnetic Stirrer?

The magnetic stir bar. Stir bars are usually made with polytetrafluoroethylene (PTFE, F4) because of its properties: heat resistance with a working range of -200 to +250°C; low-temperature performance at -196°C retaining 5%; resistance to strong acids, alkalis, aqua regia and organic solvents; electrical insulation whose dielectric properties are independent of temperature and frequency; very low friction; nonstick behavior; and nontoxicity.

Some suppliers instead use ordinary plastic. Although inexpensive, it wears rapidly and lacks heat and corrosion resistance. It may contaminate the liquid and seriously affect experimental results.

Meiyingpu's magnetic stir bars use PTFE throughout the encapsulation to support reliable experiments.