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.
V&P Scientific Inc STIR ELEMENT, DISC, NdFeB Magnet, 48MGO, Parylene C Coated, Used in Syringes, Tubes/Vials, 10/pack
STIR ELEMENT, DISC, NdFeB Magnet, 48MGO, Parylene C Coated, 6.4mm Diameter, 0.7mm Height, 80°C Max Operating Temp for Magnets
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 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.
Electron Microscopy Sciences Spinbar Circulus™ Dumbbell Stiriing Bar 52mm Yellow
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: Yellow
Electron Microscopy Sciences Spinbar Circulus™ Dumbbell Stiriing Bar 52mm White
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: White
Electron Microscopy Sciences Wood Stirring Rods
Smooth 8" long hardwood. One end flat for mashing, one end sharply pointed for pin-point stirring.
Cowie Technology Corporation STIR BAR 13X17 DBL CROSS-HEAD
PTFE Stir Bar, Crosshead Double - 13mm Ht x 17mm
Sigma Aldrich Fine Chemicals Biosciences SpinbarR magnetic stirring
Very small efficient stirring bars. Ideal for vials micro test tubes centrifuge tube mixing etc.PTfE(R) PTfE coatedALNICO V coated magnet
Sigma Aldrich Fine Chemicals Biosciences SpinbarR disposable magnet
for single-use application where efficiency and cross-contamination are a concern. Alnico V magnet.
Sigma Aldrich Fine Chemicals Biosciences SpinbarR disposable magnet
for single-use application where efficiency and cross-contamination are a concern. Alnico V magnet.
Hach Company Stir Bar, Micro, 3 x 10 mm
Use micro stir bar for mixing in vials, test tubes, spectrophotometer cells and other small-volume containers. Usable at temperatures up to 260°C. Alnico V magnet encapsulated in PTFE.