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.
Electron Microscopy Sciences PTFE Magnetic Stirrer, 50-800 RPM
All parts are fully encapsulated in a "PTFE" body so stirrer is totally inert to the most aggressive laboratory conditions. Features a speed display, reversible spin mode, no heat transfer to media, and stutter free motion. 24 Volt stepper motor with controlled acceleration and deceleration and stall detection. Ambient temperature range 0 – 40 degree C. PFA covered lead cable fused into body.
RPM: 50-800
Research Products International Corp Spinbar Magnetic Sink Strainer, Blue
The Spinbar Magnetic Sink Strainer provides an innovative solution to a common laboratory inconvenience. Prevents magnetic stirring bars from accidentally slipping into the drain when cleaning beakers or cylinders. Flexible chemical resistant strainer has four strong magnets that attract and hold stirring bars. The strainer is designed with long slits that allow unobstructed drainage of fluids. Strainer remains securely in place and fits a variety of sinks. Flat edge allows strainer to be placed near the sink wall.
Electron Microscopy Sciences Spinbar Circulus™ Dumbbell Stiriing Bar 52mm Blue
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: Blue
Electron Microscopy Sciences 18 Polygon Spin Bar Assortment Box
18 Polygon stirring bars: PTFE. consists of 2 each: 10mmx6mm, 15mmx6mm, 20mmx7mm, 25mmx8mm, 30mmx8mm, 40mmx8mm, 50mmx8mm, 60mmx8mm, 80mmx10mm.
Research Products International Corp Rare Earth Cobalt Spinbar, Octagon, Teflon Coated, 1 x 3/8 Inches
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.
Electron Microscopy Sciences Veco Parallel Bar with Handle Grid R300, Copper
Veco Grids offer superior handling characteristics. Plus, with a 0.8 mil thickness, Veco Grids are the most rigid grids available. 3.05 mm diameter.
Material: Copper
Pitch: 85 µm
Hole: 45 µm
Bar: 38 µm
Ace Glass, Inc. Stirbar, borosilicate glass, round, 12mm x 5mm
Stirbar, borosilicate glass, round, 12mm x 5mm
Electron Microscopy Sciences Veco Parallel Bar with Divider R100Aspec, Nickel
Veco Grids offer superior handling characteristics. Plus, with a 0.8 mil thickness, Veco Grids are the most rigid grids available. 3.05 mm diameter.
Material: Nickel
Pitch: 250 µm
Hole: 200 µm
Bar: 50 µm
Integra Biosciences Corp Magnetic stir bar - for homo
Magnetic stirrer bar - for homogeneous medium mixing within the cuvette
Research Products International Corp Octagon Spinning Stir Bar, 1 1/2 x 1/2 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.