Stirring Bars and Rods
Stirring Bars and Rods
Products of various sizes, shapes, and material compositions designed to aid in manual or automatic stirring of laboratory solutions. Includes glass stirring rods, magnetic stir bars, and stir bar retrievers.
What Is a Magnetic Stir Bar?
Magnetic stir bars are stirrers or stirring hotplates used with magnets to mix a liquid or solution by creating a vortex.
A number of factors affect magnetic stir bar efficiency and effectiveness, including its size, shape, and material. Sizes (L x Diameter) range from 2 x 2 mm to 159 x 27 mm and shapes include:
- Polygonal or octagonal magnetic stir bars are the most common shapes; the multiple surfaces add turbulence to the mixing action
- Elliptical or egg-shapped stir bars work especially well with round-bottom flasks
- Wedge-shaped spin bars produce more significant turbulence for dissolving salts or in samples containing sediment
- Spin bars with fins or vanes, designed for smaller vessels, tubes, or cuvettes
- Micro (“flea”) stir bars for mixing extremely small samples
What Kind of Magnet Is Used?
Stir bar magnets are typically made from Alnico, a combination of aluminum and nickel. They may also be made from Samarium cobalt, a rare earth metal that produces the stronger magnetic force needed to mix very viscous substances.
Stir bar magnets are usually encapsulated in white or colored PTFE, hard plastic, or borosilicate glass, and coatings may meet FDA grade or USP requirements. PTFE is durable, inert, and can be autoclaved. Glass-encased cylindrical magnets are useful for high-temperature applications.
How Does It Work?
During the stirring process, integral or removable pivot rings on the stir bar reduce contact with the vessel to help avoid marring plastic surfaces. Some round stir bars have slightly raised ends that create a de facto pivot point, while others have more pronounced round centers that help to keep them in motion. Stir bars may be reusable or disposable.
Magnetic stir bars may be sold individually or in magnetic stir bar kits that include multiple bars in a range of sizes.
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.
Promotions are available
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.
Azlon™ Oval Magnetic Stirrer Bar
Use these bars in for a variety of stirring applications. Azlon™ Oval Magnetic Stirrer Bars are ideal for round bottomed flasks.
SI Analytics™ PTFE Coated Magnetic Stirrer Rod Set
SI Analytics™ PTFE Coated Magnetic Stirrer Rod Set is designed for use in standard applications.
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.
Promotions are available
Fisherbrand™ PTFE Micro Magnetic Stir Bar
Designed for the smallest containers. Fisherbrand™ PTFE Micro Magnetic Stir Bar are autoclavable.
Fisherbrand™ PTFE Magnetic Stir Bars with Pivot Ring
Used in containers with bases that are slightly curved or uneven.
Fisherbrand™ PTFE Magnetic Stir Bar, Cross-shaped
Use with containers, vessel, stirrers, and stirring hot plates. The PTFE-coated magnet stirrers are stable for many general purpose applications. The bars are cross-shaped for improved stirring action.
Fisherbrand™ PTFE Magnetic Stir Bar, Cross-shaped
Use with containers, vessel, stirrers, and stirring hot plates. Fisherbrand™ PTFE Magnetic Stir Bar, Cross-shaped, offer improved stirring action.
Cowie Technology™ PTFE Plain Stirring Magnets
Gives turbulence at low speeds.
Fisherbrand™ PTFE Magnetic Stir Bar, Single-sided crosshead
Designed for use with tube-like containers yet very effective as general stirrers. The PTFE-coated magnet stirrers include a crosshead on one side of the stirrer.
Fisherbrand™ PTFE Magnetic Stir Bar, Double-sided crosshead
Designed for use with tube-like containers yet very effective as general stirrers. The PTFE-coated magnet stirrers include a crosshead on both sides of the stirrer for greater turbulence.
Azlon™ Cylindrical Stirrer Bar
Available in a range of lengths. Azlon™ Cylindrical Stirrer Bar is suitable for a wide range of flat bottomed containers.
BRAND™ Triangular Wedge-Shape PTFE Magnetic Stirring Bars
An excellent option for liquid agitation in the laboratory.
