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, 10mm Length, Dia. 5mm
Magnetic stirring Bar - Z type, 10mm length, Dia. 5mm
Sigma Aldrich Fine Chemicals Biosciences SpinbarR PyrexR magnetic s1EA
SPINBARR SpinbarR PyrexR magnetic s1EA
Sigma Aldrich Fine Chemicals Biosciences BRAND(R) magnetic stirring bar, PTFE, cylindrical L 40 mm, bar diam. 8 mm | 10EA
BRAND(R) magnetic stirring bar, PTFE, cylindrical L 40 mm, bar diam. 8 mm | 10EA
Sigma Aldrich Fine Chemicals Biosciences CORNING MAG STIR BAR RETRIEVER
NC3848688 CORNING MAG STIR BAR RETRIEVER
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
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
BIG SCIENCE INC GIANT PLAIN STIR BAR 6IN 1IN D
Giant Plain Stir bar: Length 159 mm (6 inches), Diameter 27 mm (1 inch)
Cole-Parmer Micro Stir Bar, 10mm L x 3mm dia 10mm L x 3mm dia.
Strong alnico V magnets with one-piece coating of PTFE.
Research Products International Corp Rare Earth Cobalt Spinbar, 3 x 1/2
Reduce frequency of spinout in viscous solutions or when stirring at high speeds. The high magnetic field strength of Samarium Cobalt (Rare Earth) magnets can provide up to three times stronger coupling vs. Alnico magnetic stirring bars. Stronger coupling with the drive magnet keeps the stirring bar centered and rotating effectively. Octagon shape with pivot ring creates strong turbulence with minimal chattering and friction. Encapsulated in bright green, FDA grade, USP Class VI Teflon PTFE; easy to differentiate from other stirring bars. Autoclave safe.
Fireflysci P68 Mixer for Semi-Micro Cuvettes (Type 9, Type 9B, Type 9BM, Type 9F, Type 9M)
Manual mixer fits any standard 10mm pathlength cuveette with a 4mm inside width• Made of clear acrylic with a straight handle, this tool is used when reactives are performed directly into cuvettes to mix added reagents. Up and down motion in cell provides complete mixing• Shaft diameter- 3.17mm (0.125 inches)