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.
Chemglass Life Sciences Stir Bar, Magnetic, PTFE, Length x Dia. in mm: 25.4 x 7.93, Length x Dia. in inches: 1 x 5/16
Stir Bar, Magnetic, PTFE, Length x Dia. in mm: 25.4 x 7.93, Length x Dia. in inches: 1 x 5/16. Octagon cross-section having a molded-in pivot ring manufactured with FDA-grade and USP Class VI PTFE. The PTFE coated Alnico magnet permits magnetic agitation without contamination.SEE CG-2001-50 FOR STIR BAR KIT
Electron Microscopy Sciences Micro Stir Bars, 3 x 10 mm
Coated with "PTFE" white resin. For stirring test tubes, micro-beakers, and more.
Size: 3 x 10 mm
Cole-Parmer 37130-9003 Egg-Shaped Stir Bar, 3" L x 3/4" Dia; 1/Pk
Egg-shaped stir bars have oval magnets—ideal for use in round-bottom flasks. Shape conforms to flask bottom and ensures complete mixing.
MSC Unger ErgoTec T-Bar, Polypropylene, Green/Black
The Unger ErgoTec T-Bar is a professional-grade tool designed for efficient and ergonomic window cleaning. It features a durable polypropylene construction, ensuring reliability and comfort for extended use in various cleaning applications.
- Constructed from polypropylene material
- Features a green and black color scheme
- Designed for ergonomic handling
- Available in multiple lengths for varied tasks
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