Fisherbrand™ Stir Bar Box Set, Cylindrical
Provides general purpose stirring for a wide variety of applications. Fisherbrand™ Stir Bar Box Sets, Cylindrical are isostatically molded in pure, FDA-approved PTFE plastic.
Fisherbrand™ Stir Bar Box Set, Oval
Guaranteed inert and leak-free. Fisherbrand™ Stir Bar Box Set, Oval is isostatically molded in pure, FDA-approved PTFE plastic.
Azlon™ Pivot Ring Magnetic Stirrer Bar
Constructed of magnetic PTFE. Azlon™ Pivot Ring Stirrer Bar includes a central pivot ring that ensures efficient spinning even on curved or uneven bases.
Fisherbrand™ Plain Economy PTFE Stir Bar
Provides stable stirring action. The plain economy PTFE magnetic stir bar work within a wide range of conditions, low prices from high-volume manufacturer.
Fisherbrand™ Stir Bar Box Set, Cross-Shaped
Provides stable, general purpose stirring. Fisherbrand™ Stir Bar Box Sets, Cross-Shaped are isostatically molded in pure, FDA-approved PTFE plastic.
Azlon™ Magnetic Retrievers for Stirrer Bars
Retrieve stirrer bars from sensitive liquids with these magnetic retrievers. Azlon™ Magnetic Retrievers for Stirrer Bars feature magnets permanently embedded in a PTFE rod.
Fisherbrand™ Cylindrical PTFE or Glass Stir Bars
Alnico V magnet core encapsulated by PTFE or glass . Fisherbrand™ Cylindrical PTFE or Glass Stir Bars are autoclavable.
Azlon™ Micro Magnetic Stirrer Bar
Use these bars in for a variety of stirring applications. Fisherbrand™ Azlon™ Micro Magnetic Stirrer Bars are ideal for small vessels, test tubes and vials.
Fisherbrand™ Octahedral PTFE Stir Bar
Provides stable stirring action. These PTFE magnetic stir bars are autoclavable and include a pivot ring. The flat surfaces provide a great mixing action.
PTFE Magnetic Stirring Bar
Stirbars designed for stirring small volumes have polygon multifaceted surfaces that add turbulence relative to similar smooth cylindrical bars.
Cowie Technology™ PTFE Cylindrical Stir Bar Box Set
Cowie Technology™ PTFE Cylindrical Stir Bar Box Set includes an assortment of useful Cylindrical Stirrer Bar sizes in a reusable container.
Fisherbrand™ Glass-Encased Stir Bar
Use with very abrasive media that may erode PTFE. The glass-encased magnetic stir bar is cylindrical for a wide variety of uses.
Buerkle™ Magnetic Stirring Bar
Molded with an outer layer of chemically inert PTFE for durability and non-reactivity. Buerkle™ Magnetic Stirring Bars feature a cylindrical shape and smooth surface for excellent mixing capability.
Fisherbrand™ Stir Bar Box Set, Octahedral
For use in containers with bases that are slightly curved or uneven. Fisherbrand™ Star Bar Box Set, Octahedral is isostatically molded in pure, FDA-approved PTFE plastic.
Magnetic stir bars, also known magnetic followers, magnetic stirrers or magnetic fleas, are small, cylindrically-shaped laboratory devices used with magnetic stirring plates to stir liquids held in suitable vessel or container such as a beaker, flask or bottle. The stir bar is introduced into the liquid, the container is placed on a magnetic stirrer, the stirrer is switched on and the bar rotates by magnetic attraction stirring the liquid. They offer the unique attraction of being able to operate inside completely sealed containers.
Stir bars typically have a magnetic Alnico (aluminium-nickel-cobalt) core coated in a protective, chemically-resistant and inert covering such as PTFE (most commonly), or glass. They are manufactured in a range of lengths and diameters to accommodate different sample sizes and vessel capacities, ranging from 1.5mm in length often up to 160mm.
Although most stir bars are smooth, round-ended cylinders, some have different cross-sectional shapes (octahedral or triangular). Others may also have a central circumferential pivot ring which helps the bar spin more effectively and to help centre it in the middle of the vessel during mixing. Other bars are shaped as ovals, crosses, cross-headed discs or spheres, all of which are designed to provide optimal turbulence and spin efficiency.
Magnetic stir bar kits offer a selection of sizes and shapes in one package to accommodate different requirements.
Magnetic stir bars have several purposes in the laboratory:
- For ensuring that solutions are well-mixed during titrations
- For dissolving solids
- For mixing miscible liquids
- For maintaining particulates in suspension