A magnetic stir bar (also known as a flea or spinbar) is a small, encapsulated magnet used in laboratories to blend liquids and solutions uniformly. It works by spinning in synchronization with an external rotating magnetic field generated by a underlying
Core Anatomy & CompositionThe Internal Magnet: Most commonly built with an Alnico V core (aluminum-nickel-cobalt) for long-lasting permanent magnetization. High-viscosity mixing instead utilizes strong rare-earth magnets like Samarium Cobalt to deliver heavy-duty torque.The Outer Shell: Typically coated in PTFE (Teflon) or borosilicate glass. The shell ensures the bar remains completely chemically inert, highly lubricated, and heat-resistant up to 250°C–260°C.