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.
Enterprise Technology Solutions Kimberly-Clark Professional Towels,C-Fold,Low Wet Strength,10.1"x13.15",200/PK,12/CT,WE
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Andwin Scientific STIR STICKS 12" 100/PK
Perfect Stix 12" Wooden Paint Paddle Stirrer Sticks Length (Pack of 100)
Electron Microscopy Sciences 18" Polypropylene Retriever
Polypropylene stirring bar retrievers are ideal for use with all stirring bars. The entire retriever is totally encased in a chemically resistant polypropylene, with a handy ring for hanging when not in use.
Electron Microscopy Sciences Stirring Rod Solid PTFE Rod, 300 mm, diameter
PTFE solid rod with tapered end, rods are inert and will not scratch. Use up to 280 deg C.
OAL: 300 mm
Hach Company Stir Bar, Magnetic, Plus Shape, 1-1/4"
This magnetic stir bar adds speed and efficiency to your mixing requirements. The “+” shape creates a deep vortex and provides stable, quiet operation.
Fisherbrand™ PTFE Stirring Rods
Pure PTFE rods with a milled steel core.