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, "X" Shaped, PTFE, 60 x 20: Diameter x Height (mm)
Stir Bar, Magnetic, "X" Shaped, PTFE, 60 x 20: 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, "X" Shaped, PTFE, 38 x 11: Diameter x Height (mm)
Stir Bar, Magnetic, "X" Shaped, PTFE, 38 x 11: 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, "X" Shaped, PTFE, 20 x 8: Diameter x Height (mm)
Stir Bar, Magnetic, "X" Shaped, PTFE, 20 x 8: 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, Glass, Length x Dia. in mm: 25.4 x 9.52, Length x Dia. in inches: 1 x 3/8
Stir Bar, Magnetic, Glass, Length x Dia. in mm: 25.4 x 9.52, Length x Dia. in inches: 1 x 3/8. Borosilicate covered Alnico magnet for use in high temperature reactions.
Chemglass Life Sciences Stir Bar, Magnetic, Triangular, PTFE, 25mm L X 8mm Diameter
Stir Bar, Magnetic, Triangular, PTFE, 25mm L X 8mm 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, Triangular, PTFE, 20mm L X 8mm Diameter
Stir Bar, Magnetic, Triangular, PTFE, 20mm L X 8mm 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.
Ace Glass, Inc. Stirbar, PTFE, octagonal, red, 22.2mmx8.0mm
Stirbar, PTFE, octagonal, red, 22.2mmx8.0mm
Biotage Magnetic Stir Bars, for 10-20 mL Microwave Reaction Vial 5/Case
Biotage Magnetic Stir Bars, for 10-20 mL Microwave Reaction Vial 5/Case
Biotage Magnetic Stir Bars, for 2-5 mL Microwave Reaction Vials 25/Case
Biotage Magnetic Stir Bars, for 2-5 mL Microwave Reaction Vials 25/Case
Biotage Magnetic Stir Bars, for 0.5-2 mL Microwave Reaction Vials 25/Case
Biotage Magnetic Stir Bars, for 0.5-2 mL Microwave Reaction Vials 25/Case
Cole-Parmer Mono-Mold Standard Stir Bar with Spinning Ring, 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.
Research Products International Corp Rare Earth Cobalt Spinbar, 3 x 1/2
Reduce frequency of spinout in viscous solutions or when stirring at high speeds. The high magnetic field strength of Samarium Cobalt (Rare Earth) magnets can provide up to three times stronger coupling vs. Alnico magnetic stirring bars. Stronger coupling with the drive magnet keeps the stirring bar centered and rotating effectively. Octagon shape with pivot ring creates strong turbulence with minimal chattering and friction. Encapsulated in bright green, FDA grade, USP Class VI Teflon PTFE; easy to differentiate from other stirring bars. Autoclave safe.
Ace Glass, Inc. Baffle, PTFE, fits #11 Ace-Thred, 330mm long, 18x150x10 baffle, can take 1/4in OD temp probe up to 500mm length.
18x150x10 PTFE baffle with an integral stainless steel tube. Can be used for either liquid addition into a reactor, or primarily as a temperature probe. Baffle fits a #11 Ace-Thred and is 330mm long. Baffle can take a 1/4 O.D. temperature probe that is up to 500mm long. The #7 Ace-Thred bottom bushing will make a tight compression seal with either the tubing or a thermocouple.
Chemglass Life Sciences Chemglass Stir Bar Retriever, PTFE, 350 x 10 mm (CG-2015T-03)
PTFE stir bar retriever designed to safely recover magnetic stir bars from reaction vessels and laboratory glassware. Molded in pure, FDA-approved PTFE for chemical inertness, the retriever is autoclavable and fitted with a strong magnetic tip for reliable pickup.
- Material: PTFE.
- Length: 350 mm.
- Diameter: 10 mm.
- Magnet options: Alnico V or rare earth.
- Autoclavable for laboratory sterilization.
- Designed for retrieval of magnetic stir bars from vessels.
