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.
Hach Company Stir Bar, 8 x 3 mm - replacement for 5500sc Ammonia Monochloramine Analyzer
Replacement magnetic stir bar for use with the 5500sc Ammonia Monochloramine Analyzer. It provides consistent mixing in the sample chamber to support accurate, continuous measurements; regular replacement is recommended to maintain analyzer performance.
- Dimensions: 8 x 3 mm.
- Suggested replacement schedule: 6 months.
- Material: not specified by the manufacturer.
- Function: maintains proper mixing in the sample chamber.
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
Cowie Technology Corporation MICRO STIRBAR 13MM L 3MM D
This item has a minimum order quantity of 143 per supplier requirements. Stirbar, micro, length 13 mm, diameter 3 mm
Cowie Technology Corporation MICRO STIRBAR 10MM L 3MM D
This item has a minimum order quantity of 193 per supplier requirements. Stirbar, micro, length 10 mm, diameter 3 mm
Cowie Technology Corporation OCTAHEDRAL STIR 13MM L 3MM D
This item has a minimum order quantity of 113 per supplier requirements. OCTAHEDRAL STIR 13MM L 3MM D
Chemglass Life Sciences Chemglass Magnetic PTFE Stir Bar, Turbo Rare-Earth, Elliptical, 15 x 10 mm
Chemglass magnetic PTFE stir bar with a rare-earth turbo magnet and an elliptical (egg-shaped) profile. It provides exceptional magnetic coupling with near-total resistance to demagnetization and is identified by an inert carbon black spot. Made in the United Kingdom.
- PTFE construction.
- Rare-earth turbo magnet for exceptional magnetic strength.
- Dimensions: 15 x 10 mm.
- Elliptical (egg-shaped) profile.
- Identified by inert carbon black spot.
- Exceptional resistance to demagnetization.
- Made in the United Kingdom.
Ace Glass, Inc. Stirbar, PTFE, octagonal, blue, 38.1mmx8.0mm
38.1mm x 8.0mm blue octagonal PTFE stirbar with pivot ring.
Ace Glass, Inc. Stirbar, PTFE, octagonal, yellow, 15.9mmx8.0mm
15.9mm x 8.0mm yellow octagonal PTFE stirbar with pivot ring.
Ace Glass, Inc. Stirbar, PTFE, octagonal, yellow, 50.8mmx8.0mm
50.8mm x 8.0mm yellow octagonal PTFE stirbar with pivot ring.
Cowie Technology Corporation GIANT PLAIN STIRBAR L57MMD27MM
This item has a minimum qty of 8 per supplier requirements.
Stirbar, giant plain, length 57 mm, diameter 27 mm
