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, Micro, Magnetic, PTFE, Length x Dia. in mm: 8 x 1.5
Stir Bar, Micro, Magnetic, PTFE, Length x Dia. in mm: 8 x 1.5. Micro PTFE stir bar for the very smallest containers. Manufactured with FDA-grade and USP Class VI PTFE.SEE CG-2003-50 FOR STIR BAR KIT
Electron Microscopy Sciences Spinbar Magnetic Sink Strainer, Green
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.
Foxx Life Sciences Borosil Reusable Solid Stirring Rods, Polished Glass Stirrers, 7mm x 205mm (Medium Length), 20/CS
Borosil Polished Glass Solid Stirring Rods are constructed from smooth, low-expansion, low-extractable borosilicate glass. Their mechanical strength, excellent heat resistance, and outstanding chemical compatibility make them the perfect general use stirrer. Borosil Glass Stirrers are avaialble in two widths: 7mm and Extra-Wide 9mm. Each width is Avail. in four lengths, from the Short 150mm to the Extra Large 305mm. In collaboration with Borosil Glass Works, Foxx Life Sciences is proud to bring the outstanding quality of Borosil Type 3.3 Borosilicate glassware to North America for the first time. Manufactured from the same USP Type 1 borosilicate glass that North American scientists have come to trust, Borosil Laboratory Glassware offers unparalleled mechanical strength, clarity, and reliability at competitive prices. And thanks to a unique annealing process, Borosil Glassware is stress-free and incredibly resistant to thermal shock.
Ace Glass, Inc. PTFE multi-paddle agitator, 76mm diameter
76mm diameter PTFE multi-paddle agitator for 10mm OD drilled or knob type shafts. Paddles are replaceable.
Cowie Technology Corporation MICRO STIRBAR 8MM L 1.5MM D
This item has a minimum order quantity of 137 per supplier requirements. Stirbar, micro, length 8 mm, diameter 1.5 mm
Sigma Aldrich Fine Chemicals Biosciences SpinbarR disposable magnet
for single-use application where efficiency and cross-contamination are a concern. Alnico V magnet.
Cowie Technology Corporation CROSS STIRBAR 10MM L 5MM D
This item has a minimum order quantity of 82 per supplier requirements. Stirbar, cross, length 10 mm, diameter 5 mm
Cowie Technology Corporation MICRO STIRBAR 10MM L 3MM D
This item has a minimum order quantity of 173 per supplier requirements. Stirbar, micro, length 10 mm, diameter 3 mm