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: 50.8 x 9.52, Length x Dia. in inches: 2 x 3/8
Stir Bar, Magnetic, PTFE, Length x Dia. in mm: 50.8 x 9.52, Length x Dia. in inches: 2 x 3/8. 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
Chemglass Life Sciences Stir Bar, Magnetic, Glass, Length x Dia. in mm: 22.2 x 6.35, Length x Dia. in inches: 7/8 x 1/4
Stir Bar, Magnetic, Glass, Length x Dia. in mm: 22.2 x 6.35, Length x Dia. in inches: 7/8 x 1/4. Borosilicate covered Alnico magnet for use in high temperature reactions.
Chemglass Life Sciences Stir Bar, Micro, Magnetic, PTFE, Length x Dia. in mm: 10 x 3
Stir Bar, Micro, Magnetic, PTFE, Length x Dia. in mm: 10 x 3. 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
Research Products International Corp Octagon Magnetic Stirring Bar, 1 1/2x3/8
Alnico magnet is encapsulated in FDA Grade, USP Class VI Teflon PTFE low friction coating; durable and inert. Interrupted profile provides greater surface area and added turbulence when compared to the smooth surface of cylindrical bars. Stirring bar is autoclavable.
V&P Scientific Inc STIR ELEMENT, CYLINDER, NdFeB Magnet, 52MGO, PEEK Encapsulated, Used in Bottles, 10/pack
STIR ELEMENT, CYLINDER, NdFeB Magnet, 52MGO, PEEK Encapsulated, 11.5mm Diameter, 48.2mm Length, 80°C Max Operating Temp for Magnets
Research Products International Corp Octagon Magnetic Stirring Bar, 1 x 5/16 Inches, 1 each
Octagon magnetic stirring bars with integral pivot ring are the most commonly used shape. Alnico magnet are encapsulated in FDA Grade, USP Class VI Teflon PTFE low friction coating; durable and inert. The interrupted profile provides greater surface area and added turbulence when compared to the smooth surface of cylindrical bars. Pivot ring aids in reducing friction and chattering. Stirring bars are autoclavable.
Chemglass Life Sciences Agitator, PTFE, High Viscosity, 5in Diameter, Fits 19mm Shaft Size, Fits 2L-5L Reactors
Agitator, PTFE, High Viscosity, 5in Diameter, Fits 19mm Shaft Size, Fits 2L-3L Reactors. High viscosity agitator, made entirely of PTFE and glass filled PTFE, provides excellent stirring at the bottom of 2L through 3L reactors, especially when heavy slurries are being mixed. Agitator attaches to stir shaft by both a compression fitting and a glass filled PTFE safety pin. Heavy duty blades are 7mm thick. Supplied complete with one glass filled PTFE safety pin.
Chemglass Life Sciences Stir Bar, Magnetic, Triangular, PTFE, 50mm L X 12mm Diameter
Stir Bar, Magnetic, Triangular, PTFE, 50mm L X 12mm Diameter. Effective for dissolving solids and mixing sediments in a flat bottom container such as a beaker or Erlenmeyer flask. Manufactured with FDA-grade and USP Class VI PTFE.
Chemglass Life Sciences Stir Bar, Magnetic, "X" Shaped, PTFE, 10 x 5: Diameter x Height (mm)
Stir Bar, Magnetic, "X" Shaped, PTFE, 10 x 5: Diameter x Height (mm). Shape of stir bar creates a deep vortex and provides stability during stirring. Manufactured with FDA-grade and USP Class VI PTFE.
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