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. Stirbar, PTFE, octagonal, blue, 25.4mmx8.0mm
25.4mm x 8.0mm blue octagonal PTFE stirbar with pivot ring.
Grainger Youth Food Bar 45 1/2 in H Black
The Carlisle Youth Food Bar is a 45 1/2 inch overall length food bar made of polypropylene plastic. It features a smooth finish and is blue in color. The food bar has a 1 3/4 inch outside diameter and comes with wall mounting hardware. It can support up to 300 lbs and is designed for use in cafeterias, breakrooms, and other food service areas to keep order when customers are waiting in line for food. The polypropylene material makes it easy to clean and durable. Overall, this is a heavy-duty food bar for organizing customers in food service settings.
Cowie Technology Corporation CROSS STIRBAR 30MM L 10MM D
This item has a minimum qty of 38 per supplier requirements.
Stirbar, cross, length 30 mm, diameter 10 mm
Cowie Technology Corporation REMOVABLE RING STIR L12MM D8MM
This item has a minimum qty of 49 per supplier requirements.
Stirbar, removable ring, length 12 mm, diameter 8 mm
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
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, 50.8mmx8.0mm
50.8mm x 8.0mm yellow octagonal PTFE stirbar with pivot ring.