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: 6.35 x 3
Stir Bar, Micro, Magnetic, PTFE, Length x Dia. in mm: 6.35 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
Chemglass Life Sciences Stir Bar, Magnetic, PTFE, Length x Dia. in mm: 15.9 x 7.93, Length x Dia. in inches: 5/8 x 5/16
Stir Bar, Magnetic, PTFE, Length x Dia. in mm: 15.9 x 7.93, Length x Dia. in inches: 5/8 x 5/16. 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
Cole-Parmer Essentials PTFE Stir Bar, Plain, 25 x 10mm
These PTFE stir bars feature a slimmer profile and larger length to diameter ratio.
Cole-Parmer DWK Life Sciences (Kimble) Stir Rod, Glass, 6.4 mm dia X 250 mm L, 25/pk
Manufactured with borosilicate glass with rounded annealed ends. Stir rods are highly chemical resistant and withstands temperatures to 400° F (205°)C. Autoclavable.
Cole-Parmer Egg-Shaped Stir Bar, 2-1/2" L x 3/4" Dia; 1/Pk
Egg-shaped stir bars have oval magnets—ideal for use in round-bottom flasks. Shape conforms to flask bottom and ensures complete mixing.
Chemglass Life Sciences Chemglass Plain PTFE Magnetic Stir Bar, 80 x 10 mm
Plain PTFE magnetic stir bar for use with laboratory magnetic stir plates. The smooth cylindrical profile provides consistent mixing and helps reduce vortexing across a range of vessel sizes. The PTFE coating offers chemical resistance and easy cleaning, while the encapsulated magnetic core ensures reliable coupling to stir plates.
- Made from PTFE for broad chemical resistance.
- Plain cylindrical profile for consistent mixing.
- Encapsulated magnetic core for reliable coupling to stir plates.
- Dimensions: 80 x 10 mm (length x diameter).
- Sold individually (each).
- Suitable for routine laboratory stirring and agitation.
Electron Microscopy Sciences Stirring Rod Solid PTFE Rod, 250 mm, 8 mm diameter
PTFE solid rod with tapered end, rods are inert and will not scratch, use up to 280 deg C.
OAL: 250 mm
Rod: 8 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 350 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 350 mm
Rod: 6 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 200 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 200 mm
Rod: 6 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 400 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 400 mm
Rod: 6 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 100 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 100 mm
Rod: 6 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 250 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 250 mm
Rod: 6 mm