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.
Ace Glass, Inc. Stirbars, PTFE, disposable, 41.3mmx8.0mm, pk/100
Stirbars, PTFE, disposable, 41.3mmx8.0mm, pk/100
Cowie Technology Corporation CROSS STIRBAR 60MM L 20MM D
This item has a minimum qty of 11 per supplier requirements.
Stirbar, cross, length 60 mm, diameter 20 mm
Cowie Technology Corporation TRIANGULAR STIRBAR L55MM D14MM
This item has a minimum qty of 27 per supplier requirements.
Stirbar, triangular, length 55 mm, diameter 14 mm
Uline Nylon Caster For Bar And Pipe Cradle Truck - Swivel, 8 X 2"
Nylon Caster For Bar And Pipe Cradle Truck-Swivel 8X2IN
Cowie Technology Corporation OCTAHEDRAL STIR 22MM L 8MM D
This item has a minimum qty of 49 per supplier requirements.
Stirbar, octahedral, length 22 mm, diameter 8 mm
Cowie Technology Corporation OCTAHEDRAL STIR 25MM L 10MM D
This item has a minimum order quantity of 100 per supplier requirements. Stirbar, octahedral, length 25 mm, diameter 10 mm
Hach Company Stir Bar 17.2 mm x 10.5 mm - Replacement for 5500sc Analyzers
Replacement stir bar for use with 5500sc analyzers. The bar's compact dimensions match the analyzer sample chamber to provide reliable agitation and consistent mixing for routine analysis.
- Dimensions: 17.2 mm x 10.5 mm.
- Designed to provide consistent mixing in small sample chambers.
- Sold as a spare part for laboratory analyzers.
- Safety Data Sheet (SDS) available from the manufacturer.
Cowie Technology Corporation MICRO STIRBAR 8MM L 3MM D
This item has a minimum order quantity of 152 per supplier requirements. Stirbar, micro, length 8 mm, diameter 3 mm
Cowie Technology Corporation OCTAHEDRAL STIR 13MM L 8MM D
This item has a minimum order quantity of 152 per supplier requirements. Stirbar, octahedral, length 13 mm, diameter 8 mm
Sigma Aldrich Fine Chemicals Biosciences SpinbarR magnetic stirring
Very small efficient stirring bars. Ideal for vials micro test tubes centrifuge tube mixing etc.PTfE(R) PTfE coatedALNICO V coated magnet