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.
Azzota Corp Magnetic Stirring Bars - Z Type, 9mm Length, Dia. 3mm
Magnetic stirring Bars - Z type, 9mm length, Dia. 3mm
Electron Microscopy Sciences 12" 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.
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.
V&P Scientific Inc STIR ELEMENT, DISC, SmCo Magnet, 29MGO, PTFE Encapsulated, 5.0mm Diameter, 1.7mm Height, 12/pack
STIR ELEMENT, DISC, SmCo Magnet, 29MGO, PTFE Encapsulated, 5.0mm Diameter, 1.7mm Height, 260°C Max Operating Temp for Coating
V&P Scientific Inc STIR ELEMENT, RECTANGLE, AlNiCo Magnet, 5.5MGO, PTFE Encapsulated, Used in Bottles, 10/pack
STIR ELEMENT, RECTANGLE, AlNiCo Magnet, 5.5MGO, PTFE Encapsulated, 25.0mm Length, 5.5mm Width, 5.5mm Height, 260°C Max Operating Temp for Coating
Electron Microscopy Sciences Spinbar Magnetic Sink Strainer, Blue
Just drop in place and prevent magnetic stirring rods from going down the sink. Made from a durable and flexible material. Includes four strong magnets to capture the magnetic stirring bars before they go down the sink drain. Features long slits so fuilds drain easily and rapidly and a wide skirt that can be used with a variety of sink drains. Four legs located on underside anchors the strainer firmly in the sink drain. One size fits most laboratory sinks.