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.
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
SIGMA ALDRICH FINE CHEMICALS BIOSCIENCES MAGNETIC STIRBAR RETRIEVER 5PK
NC2177040 MAGNETIC STIRBAR RETRIEVER 5PK
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.
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 10mL-100mL flask, Length x Dia. in inches: 3/4 x 3/8
Stir Bar, Magnetic, Egg-shaped, fits 10mL-100mL flask, Length x Dia. in inches: 3/4 x 3/8. 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 Chemglass X-Shaped PTFE Magnetic Stir Bar, 10 x 5 mm, Pack of 100 - For Magnetic Stirrers
Chemglass X-shaped PTFE magnetic stir bars (10 x 5 mm) are designed to create a deep vortex and provide stable stirring in laboratory vessels. Supplied bulk-packed in quantities of 100 (P100), these PTFE-coated stir bars are manufactured with FDA-grade, USP Class VI materials and are suitable for routine mixing on magnetic stirrers.
- 10 x 5 mm (diameter x height)
- PTFE construction, FDA-grade and USP Class VI
- X-shaped design creates a deep vortex and improves stability during stirring
- Bulk packed - 100 per pack (P100)
- Designed for use with magnetic stirrers
Cole-Parmer Glass Stir Rods with Rubber Policeman, 8" 12/pk
Glass stir rods are manufactured with soft borosilicate glass with both ends rounded. They come with a pre-assembled, removable rubber policeman for transferring liquids or clearing precipitate out of containers. Glass rods are chemically resistant and can withstand temperatures to 400°F (205°C) (without rubber policemen). Autoclavable.
Chemglass Life Sciences Chemglass Stir Bar Retriever, PTFE, 350 x 10 mm (CG-2015T-03)
PTFE stir bar retriever designed to safely recover magnetic stir bars from reaction vessels and laboratory glassware. Molded in pure, FDA-approved PTFE for chemical inertness, the retriever is autoclavable and fitted with a strong magnetic tip for reliable pickup.
- Material: PTFE.
- Length: 350 mm.
- Diameter: 10 mm.
- Magnet options: Alnico V or rare earth.
- Autoclavable for laboratory sterilization.
- Designed for retrieval of magnetic stir bars from vessels.
SIGMA ALDRICH FINE CHEMICALS BIOSCIENCES MAGNETIC STIRBAR 10X5MM 10PK
NC2177042 MAGNETIC STIRBAR 10X5MM 10PK
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 250mL-500mL flask, Length x Dia. in inches: 1 1/4 x 5/8
Stir Bar, Magnetic, Egg-shaped, fits 250mL-500mL flask, Length x Dia. in inches: 1 1/4 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