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.
Bellco Glass, Inc. PTFE Stirring Bar,41.3mm
Molded, seamless Teflon construction ideal for procedures using all bellco magnetic stirrers. Excellent for mixing media and buffer solutions. Size: 41.3 x 9.5mm Case qty: 6
MSC ADB Hoist Rings Hoist Ring, Center Pull, Screw-On, 5000 lb Capacity, 3/4-10 Thread
This hoist ring is engineered for reliable and secure lifting operations, featuring a screw-on design for easy installation. With a substantial load capacity and durable construction, it is suitable for various industrial and heavy-duty applications requiring controlled lifting.
- Center pull type
- Screw-on design
- 5000 lb load capacity
- 3/4-10 thread size
- Black oxide alloy steel material
- 6.72 in ring height
- 1.53 in thread length
- 100 ft/lb torque
Cole-Parmer AZS4235 Stir Bars, 12 x 4.5 mm; 10/PK
Keep your reaction station running smoothly with these parts and accessories.
Electron Microscopy Sciences Micro Stir Bars, 2 x 7 mm
Coated with "PTFE" white resin. For stirring test tubes, micro-beakers, and more.
Size: 2 x 7 mm
Electron Microscopy Sciences Micro Stir Bars, 1.5 x 8 mm
Coated with "PTFE" white resin. For stirring test tubes, micro-beakers, and more.
Size: 1/16 x 5/16"
Research Products International Corp Octagon Magnetic Stirring Bar, 1 x 5/16 Inches, 1 each
Octagon magnetic stirring bars with integral pivot ring are the most commonly used shape. Alnico magnet are encapsulated in FDA Grade, USP Class VI Teflon PTFE low friction coating; durable and inert. The interrupted profile provides greater surface area and added turbulence when compared to the smooth surface of cylindrical bars. Pivot ring aids in reducing friction and chattering. Stirring bars are autoclavable.
Bellco Glass, Inc. PTFE Stirring Bar,82.6mm
Molded, seamless Teflon construction ideal for procedures using all bellco magnetic stirrers. Excellent for mixing media and buffer solutions. Size: 82.6 x 19mm Case qty: 2