The Bel-Art Scienceware F371520000 Spinbar stir bar is a polygonal stir bar with Teflon (PTFE) casing and internal alnico V (an alloy of aluminum, nickel, iron, and cobalt) magnet that spins freely in a disk-shaped PS capsule, for laboratory stirring applications such as pH adjustment. The capsule reduces turbulence, centers the bar, prevents spin out, protects probes and other instruments in the container with the bar, and isolates the bar from chemicals. The polygonal stir bar has a Teflon (PTFE) casing, which is chemically inert, can be used with corrosive chemicals, and helps reduce friction and wear while spinning. The capsule is made from polystyrene (PS), which resists wear. The capsule spins on the bottom of the container to disperse sediment and air bubbles. The bar has an internal magnet made from alnico V, an alloy of aluminum, nickel, iron, and cobalt. The capsule measures 2.1" (5.3 cm) in diameter by 0.5" (1.3 cm) high. The Teflon (PTFE) and PS materials used are FDA approved for use in pharmaceutical, quality assurance, and laboratory applications. The capsule and bar disassemble for cleaning.
Magnetic stir bars (sometimes called stirring bars, spin bars, or fleas) are used to stir a liquid or solution in biological, chemical, medical, and research laboratory applications. The stir bar is placed inside a container of liquid or solution that is seated on a magnetic stirrer (also called a magnetic mixer), which is a laboratory device that creates a rotating magnetic field using a rotating magnet or multiple stationary electromagnets. The rotating magnetic field causes the bar to spin, which stirs the liquid or solution. Stirring bars are offered in a variety of sizes and shapes, and they are encased in materials such as glass or plastic to help prevent contamination of the liquid or solution, to reduce friction, and to provide resistance to chemicals, abrasion, and heat. The bar may have a pivot ring or pivot point to minimize contact with the container, reduce friction, and improve its spinning. The size and shape of the container and the volume and viscosity of the liquid or solution to be stirred determine which stir bar shape, size, and casing will suit a particular application.
Bel-Art Products manufactures scientific products, including labware, testing equipment, and safety supplies, under the Bel-Art and Scienceware brands. The company, founded in 1946, is headquartered in Wayne, NJ.