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.
Sigma Aldrich Fine Chemicals Biosciences BRAND MAGNTC STIRBAR OVAL 20MM
NC3369712 BRAND MAGNTC STIRBAR OVAL 20MM
Electron Microscopy Sciences Rubber Policeman | 12/Box
Policeman is rubber cover to fit 5mm rods. The sealed end is cut at an angle to help stir at the bottom of container.
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.
Research Products International Corp Octagon Magnetic Stirring Bar, 2 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.
Research Products International Corp Octagon Spinning Stir Bar, 1 1/2 x 1/2 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.
Cole-Parmer Mono-Mold Standard Stir Bar, 3"L x 1/2" dia
Use this mono-mold standard stir bar with your large-capacity stirrers and hot plate stirrers.
Cole-Parmer Glass Stir Rods with Rubber Policeman, 8" 12/pk
Glass stir rods are manufactured with soft borosilicate glass with both ends rounded. They come with a pre-assembled, removable rubber policeman for transferring liquids or clearing precipitate out of containers. Glass rods are chemically resistant and can withstand temperatures to 400°F (205°C) (without rubber policemen). Autoclavable.
Cole-Parmer Essentials PTFE Stir Bar, Plain, 25 x 10mm
These PTFE stir bars feature a slimmer profile and larger length to diameter ratio.
BIOLOGIX USA INC CELL CULTR DISH 60X20MM W/STIR
Weight: 0.88 lbs▪ Mesh membrane material: Nylon▪Frame material： PS▪ Mesh membrane thickness: 10 ~ 23 μm▪ Membrane pore size: 0.40 μm
Analytical Sales & Services MAGNETIC STIR BARS, PTFE CTD
Magnetic Stir Bars, PTFE Coated, 5mm x 2mm. Pk100
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.