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.
Koehler Instrument Company Inc KOEHLER INSTRUMENT COMPANY INC
NC3946967 BEARING 3/16X5/16IDX2 L SLEEVE
Chemglass Life Sciences Stir Bar Kit, Magnetic, Egg-Shaped, PTFE
Stir Bar Kit, Magnetic, Egg-Shaped, PTFE. Stir Bar Kit, Magnetic, Egg-Shaped, PTFE, to consist of the following: 6ea CG-2005-10, 6ea CG-2005-12, 3ea CG-2005-14, 2ea CG-2005-15, 1ea CG-2005-16PLEASE NOTE: STIR BAR KITS ARE AVAILABLE WITH AN ASSORTMENT OF OTHER STYLES AND SIZES. PLEASE CONTACT TECHNICAL SERVICE FOR MORE INFO.
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 300mL-500mL flask, Length x Dia. in inches: 1 1/2 x 5/8
Stir Bar, Magnetic, Egg-shaped, fits 300mL-500mL flask, Length x Dia. in inches: 1 1/2 x 5/8. 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
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 500mL-1000mL flask, Length x Dia. in inches: 1 5/8 x 3/4
Stir Bar, Magnetic, Egg-shaped, fits 500mL-1000mL flask, Length x Dia. in inches: 1 5/8 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
Research Products International Corp Octagon Magnetic Stirring Bar, 1 1/2x5/16
Octagon magnetic stirring bars with integral pivot ring are the most commonly used shape. Alnico magnet is 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.
Sigma Aldrich Fine Chemicals Biosciences SpinbarR magnetic stir bar1EA
Leakproof seamless polished and contains a permanent Alnico V magnet. Egg-shape bar is designed especially for use in round-bottom vessels.
Chemglass Life Sciences Stir Bar, Giant, Magnetic, PTFE, Length x Diameter: 108 x 27mm / 4-1/4 x 1-1/16 inches
Stir Bar, Giant, Magnetic, PTFE, Length x Diameter: 108 x 27mm / 4-1/4 x 1-1/16 inches. This heavy duty PTFE stir bar is capable of mixing volumes up to a 50 gallon drum. Perfect for use with carboys up to 12 gallon. The bar will fit into a minimum neck diameter of 32mm. Manufactured with FDA-grade and USP Class VI PTFE.