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.
Analytical Sales & Services Well Tray Loaded with Barcoded 8x30 Shell Vials, with 99685 Silicone Cap Mat, and 13258 Stir Bars
Well Tray Loaded with Barcoded 8x30 Shell Vials, with 99685 Silicone Cap Mat, and 13258 Stir Bars
Ace Glass, Inc. Stirbar, borosilicate glass, round, 12mm x 5mm
Stirbar, borosilicate glass, round, 12mm x 5mm
Chemglass Life Sciences Stir Bar, Magnetic, PTFE, Turbo, Rare Earth, Elliptical, 70 x 28mm
Exceptional strength coupled with almost total resistance to demagnetisation. Identified by an inert carbon black spot.
Chemglass Life Sciences Agitator, PTFE, High Viscosity, 7.5in Diameter, Fits 19mm Shaft Size, Fits 10L-15L Reactors
Agitator, PTFE, High Viscosity, 7.55in Diameter, Fits 19mm Shaft Size, Fits 10L-15L Reactors. High viscosity agitator, made entirely of PTFE and glass filled PTFE, provides excellent stirring at the bottom of 10L through 15L 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, "X" Shaped, PTFE, 30 x 10: Diameter x Height (mm)
Stir Bar, Magnetic, "X" Shaped, PTFE, 30 x 10: 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.
Electron Microscopy Sciences Micro Stir Bars, 1.5 x 15 mm
Coated with "PTFE" white resin. For stirring test tubes, micro-beakers, and more. Packed 12 bars per box. 1/16 x 9/16 inches; 1.5x15mm
Ace Glass, Inc. Stirbar, PTFE, x shape, for microscale vials, 25.4mmx25.4mm
Stirbar, PTFE, x shape, for microscale vials, 25.4mmx25.4mm
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 3000mL-5000mL flask, Length x Dia. in inches: 2 1/2 x 3/4
Stir Bar, Magnetic, Egg-shaped, fits 3000mL-5000mL flask, Length x Dia. in inches: 2 1/2 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
Electron Microscopy Sciences Spinbar Circulus™ Dumbbell Stiriing Bar 52mm Red
These magnet stirring bars provide strong turbulence at relatively low speeds, offering reduced surface contact and excellent centering characteristics, particularly in vessels with convex bottoms. Ideal for 'problem' liquids, highly viscous mixtures and metal particles in fluid. All sizes have solid PTFE end disks 20 mm (.79”) in diameter. Bar diameter is 8 mm (.315”).
Color: Red
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.
V&P Scientific Inc STIR ELEMENT, CYLINDER, AlNiCo Magnet, 5.5MGO, PTFE Encapsulated, Used in Bottles, Microplates, Tubes/Vials, 10/pack
STIR ELEMENT, CYLINDER, AlNiCo Magnet, 5.5MGO, PTFE Encapsulated, 3.0mm Diameter, 20.0mm Length, 260°C Max Operating Temp for Coating