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 Retriever, Polypropylene, 3/8in Dia. x 18in OAL
Stir Bar Retriever, Polyethylene, 3/8in Dia. x 18in OAL. A 3/8" diameter pick up rod with a powerful Alnico magnet in one end and hang up grip on the other.
Electron Microscopy Sciences 18" Polypropylene Retriever
Polypropylene stirring bar retrievers are ideal for use with all stirring bars. The entire retriever is totally encased in a chemically resistant polypropylene, with a handy ring for hanging when not in use.
GA International Destructible Cryogenic Labels for Vials & Containers 1.625" x 0.625" / 41.3mm x 15.9mm Rectangle White From -196°C to +100°C (-321°F to +212°F)
Destructible labels, designed for the secure identification of cryo vials, microtubes, and other containers. This includes cardboard and cryo boxes, plates, vials, and where visible evidence of label tampering is required, such as in pharmaceutical applications. Once adhered to the surface, the labels cannot be removed without being destroyed and broken into small pieces. These cryogenic labels will withstand prolonged storage in laboratory freezers, transport on dry ice, and thawing in water baths. Can be printed with thermal-transfer printers or handwritten with our permanent cryogenic markers.
Cowie Technology Corporation OCTAHEDRAL STIR 38MM L 8MM D
This item has a minimum qty of 41 per supplier requirements.
Stirbar, octahedral, length 38 mm, diameter 8 mm
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 12000mL-22000mL flask, Length x Dia. in inches: 3 x 3/4
Stir Bar, Magnetic, Egg-shaped, fits 12000mL-22000mL flask, Length x Dia. in inches: 3 x 3/4. Egg-shaped magnetic stirring bar provides its own pivot point without separate ring or abrupt change in contour. Designed for use in round bottom vessels, it is shaped to spin freely, unrestricted by the vessel contour. Manufactured with FDA-grade and USP Class VI PTFE.SEE CG-2005-20 FOR STIR BAR KIT
Cole-Parmer Mono-Mold Standard Stir Bar, 1-1/2"L x 3/8" dia
Mono-Mold magnetic stir bars are the standard all-purpose stir bar. Available with or without spinning rings; rings reduce contact area between stir bar and vessel, reducing friction and noise.