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.
Azzota Corp Magnetic Stirring Bars - Z Type, 5mm Length, Dia. 3mm
Magnetic stirring Bars - Z type, 5mm length, Dia. 3mm
Sigma Aldrich Fine Chemicals Biosciences SpinbarR disposable magnet
for single-use application where efficiency and cross-contamination are a concern. Alnico V magnet.
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.
Chemglass Life Sciences Stir Bar, Magnetic, Egg-shaped, fits 5mL-25mL flask, Length x Dia. in inches: 3/8 x 3/16
Stir Bar, Magnetic, Egg-shaped, fits 5mL-25mL flask, Length x Dia. in inches: 3/8 x 3/16. 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 10mm PTFE Stirrer Bearing, 24/40, #018 Body O-Ring, #013 Bushing O-Ring
Grease-Free PTFE stirrer bearing for use under moderate vacuum. The bearing consists of a PTFE standard taper body, PEEK (Polyetheretherketone) compression cap, PTFE Insert/bushing and a Nylon loosening nut. The PTFE insert/bushing provides only glass and PTFE contact with the reaction. Loosening nut above the standard taper inner joint allows easy and quick removal. Supplied complete with a Perfluoro o-ring on the body and a Viton o-ring on the bushing.
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
Chemglass Life Sciences Stir Bar Dual Purpose Positioner/Retriever, Polyethylene, 5/8" Diameter X 12" OAL
Stir Bar Dual Purpose Positioner/Retriever, Polyethylene, 5/8" Diameter X 12" OAL. Convenient dual purpose polyethylene unit permits positioning of the spinbar at the bottom of a vessel without dropping bar into liquid. Also allows bar to be removed without touching or pouring out liquid. Retriever slides within outer casing. To pick up spinbar, slide retriever down; to release bar, slide retriever up. 5/8in in diameter and 12in overall length.
Cole-Parmer Mono-Mold Standard Stir Bar, 3"L x 1/2" dia
Use this mono-mold standard stir bar with your large-capacity stirrers and hot plate stirrers.
Electron Microscopy Sciences Willco-dish Glass Bottom Kit Assembly Device 50x20 mm, 12 mm Glass Aperture
Round, anodized, aluminum “Assembly Devices" for a quick, accurate and safe positioning and assembly of the glass coverslip and the adhesive ring. 50x20 mm.
Aperture: 12 mm