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.
Cowie Technology Corporation OCTAHEDRAL STIR 15MM L 8MM D
This item has a minimum order quantity of 112 per supplier requirements. Stirbar, octahedral, length 15 mm, diameter 8 mm
Azzota Corp Magnetic Stirring Bars, L Type, 35mm Length, Diameter: 11mm
Magnetic stirring Bars, L type, 35mm length, Diameter: 11mm
Azzota Corp Magnetic Stirring Bars - Z Type, 6mm Length, Dia. 5mm
Magnetic stirring Bars - Z type, 6mm length, Dia. 5mm
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 100mL- 250mL flask, Length x Dia. in inches: 1 x 1/2
Stir Bar, Magnetic, Egg-shaped, fits 100mL- 250mL flask, Length x Dia. in inches: 1 x 1/2. 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
Enterprise Technology Solutions Teacher Created Resources Magnetic Hook, 1"Wx1-1/2"Lx1/10"H, 2/PK, Gray
Magnetic hook features a super-strong, neodymium magnet to securely hold or hang heavy objects throughout your classroom. Smooth exterior sits cleanly on surfaces to prevent damaging delicate areas. Hook holds approximately 20 lb. from a vertical position, 10 lb. from a horizontal position on heavy steel, 1 lb. on a whiteboard, and 8 lb. on a metal door.
Thomas Scientific Stir Bar, Cylindrical, PTFE, 15mm, Bag of 2
Produced from PTFE For the stirring of liquids on magnetic stirrers and/or hotplate stirrers Strong alloy magnets sheathed in pure white inert PTFE Supplied in polarity aligned packs to ensure maximum coupling strength Resistant to virtually all chemical attack and temperatures up to 260°C
