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.
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 PyrexR magnetic s1EA
SPINBARR SpinbarR PyrexR magnetic s1EA
Enterprise Technology Solutions Deflecto Mounting Bar, Storage Organizer, 22" L, Gray
Wall-Mounting Bar features an easy-to-use design to make installation fast and simple. Durable aluminum construction is capable of holding up to 40 lb. to keep your supplies in a convenient location. This 22" mounting bar is designed for use with Deflecto Stackable Caddy Organizer Canisters and Interlocking Single Tilt Bins (each not included) to store a variety of essential items in one place.
Ace Glass, Inc. Stirbars, PTFE, disposable, 50.8mmx8.0mm, pk/100
Stirbars, PTFE, disposable, 50.8mmx8.0mm, pk/100
Cowie Technology Corporation TRIANGULAR STIRBAR L35MM D9MM
This item has a minimum qty of 45 per supplier requirements.
Stirbar, triangular, length 35 mm, diameter 9 mm
Electron Microscopy Sciences Spinbar Circulus™ Dumbbell Stiriing Bar 52mm Red
These magnet stirring bars provide strong turbulence at relatively low speeds, offering reduced surface contact and excellent centering characteristics, particularly in vessels with convex bottoms. Ideal for 'problem' liquids, highly viscous mixtures and metal particles in fluid. All sizes have solid PTFE end disks 20 mm (.79”) in diameter. Bar diameter is 8 mm (.315”).
Color: Red
Electron Microscopy Sciences Magnetic Stirring and Mixing Bars, 50.8 mm L, 8 mm diameter
These bars are designed for single use applications where efficiency and cross contamination is a concern. These economical bars have a "PTFE" coating which is chemically inert for high purity contact. The magnet is an Alnico V.
OAL: 50.8 mm
Diameter: 8 mm
Electron Microscopy Sciences Spinbar Circulus™ Dumbbell Stiriing Bar 52mm Yellow
These magnet stirring bars provide strong turbulence at relatively low speeds, offering reduced surface contact and excellent centering characteristics, particularly in vessels with convex bottoms. Ideal for 'problem' liquids, highly viscous mixtures and metal particles in fluid. All sizes have solid PTFE end disks 20 mm (.79”) in diameter. Bar diameter is 8 mm (.315”).
Color: Yellow