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.
Bel-Art™ Magnetic Stirring Bar Arrester
Prevents stirring bars from pouring out when emptying containers.
Wilmad Labglass STIR BRNG 10MM PTFE COMP 24/40
Stirrer Bearing, Precision, PTFE, Complete, 10mm. Joint Size: [ST] 24/40. Complete assembly includes PTFE Stirrer Bearing, PTFE bushing, saddle O-Ring, threaded heavy wall glass adapter and top screw cap.
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, Magnetic, Egg-shaped, fits 2000mL-3000mL flask, Length x Dia. in inches: 2 x 3/4
Stir Bar, Magnetic, Egg-shaped, fits 2000mL-3000mL flask, Length x Dia. in inches: 2 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
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 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
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 Stir Bar Retriever, PTFE, 450 x 10 mm - For magnetic stir bars
Designed to recover magnetic stir bars from deep reaction vessels, this PTFE-coated stir bar retriever measures 450 x 10 mm and provides chemically inert, autoclavable performance. Its long shaft and magnetic tip allow safe, convenient retrieval without contaminating samples.
- Inert PTFE construction for chemical resistance.
- 450 x 10 mm length and diameter for deep vessels.
- Autoclavable for laboratory reuse.
- Molded in FDA-approved PTFE for leak-free performance.
- Available with Alnico V or rare earth magnet options.
- Designed to retrieve magnetic stir bars without sample contamination.
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 Chemglass Stirring Bar, Plain PTFE Magnetic, 20 x 6 mm (For magnetic stir plates)
PTFE plain magnetic stirring bar, 20 x 6 mm, designed for use with magnetic stir plates to provide consistent mixing. The plain shape increases turbulence at low speeds compared with smooth cylindrical bars, and the PTFE construction offers broad chemical resistance suitable for common laboratory applications.
- PTFE construction for chemical resistance.
- Plain shape increases turbulence at low stirring speeds.
- 20 x 6 mm size for small to medium vessels.
- Magnetized for use with magnetic stir plates.
- Sold individually (each).