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 Stirring Rod Solid PTFE Rod, 250 mm, 8 mm diameter
PTFE solid rod with tapered end, rods are inert and will not scratch, use up to 280 deg C.
OAL: 250 mm
Rod: 8 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 200 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 200 mm
Rod: 6 mm
Electron Microscopy Sciences Stirring Rod PTFE with Steel Core, 100 mm, 6 mm diameter
Steel core can be bent into a permanent shape, rods are inert and will not scratch, use up to 280 degree C, rod OD: 6 mm.
OAL: 100 mm
Rod: 6 mm
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 disposable magnet
for single-use application where efficiency and cross-contamination are a concern. Alnico V magnet.
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
Ace Glass, Inc. PTFE banana stir blade, 21x87mm, 500mL flask size, 10mmshafts
21X87MM PTFE STIR BLADE
GA International Blackout Paper Labels 1.625" x 1.375" / 41.3mm x 34.9mm Rectangle White From -54°C to +93°C (-65.2°F to +199.4°F)
Permanent blackout paper labels with a unique opaque design that allows them to obscure any existing printed information, including serial numbers, barcodes, and text. Perfectly suited for general office use, laboratory, and warehouse applications, these cover-up labels are available in roll format and compatible with all standard thermal-transfer barcode printers.
Chemglass Life Sciences Stir Bar, Giant, Magnetic, PTFE, Length x Diameter: 159 x 27mm / 6-1/4 x 1-1/16 inches
Stir Bar, Giant, Magnetic, PTFE, Length x Diameter: 159 x 27mm / 6-1/4 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, 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.
Sigma Aldrich Fine Chemicals Biosciences SpinbarR PyrexR magnetic s1EA
SPINBARR SpinbarR PyrexR magnetic s1EA
Electron Microscopy Sciences Rubber Policeman | 12/Box
Policeman is rubber cover to fit 5mm rods. The sealed end is cut at an angle to help stir at the bottom of container.
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.