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.
Anton Paar Pack of 10 PTFE coated stir bars (3x10 mm)
Pack of 10 cylindrical PTFE coated stir bars (3x10 mm) for use with 10 mL Reaction Vial G10, item NC1110206.Suitable for use with Anton Paar Monowave 50
Electron Microscopy Sciences PTFE Magnetic Stirrer USA, 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
Chemglass Life Sciences Chemglass X-Shaped PTFE Magnetic Stir Bar, 20 x 8 mm, Pack of 100
Chemglass X-shaped PTFE magnetic stir bars are bulk-packed stir bars designed for use with laboratory magnetic stirrers. Each bar measures 20 x 8 mm; the pack contains 100 pieces for bulk laboratory use.
- Ptfe construction provides chemical resistance and broad solvent compatibility.
- X-shaped profile creates a deep vortex and provides stability during stirring.
- 20 x 8 mm size is suitable for small to medium vessels.
- Pack of 100 supplies laboratories with a bulk quantity for routine use.
- White color allows easy visibility in clear solutions.
Andwin Scientific Stir bars egg-shaped, Spinbar, 1 each
Spinbar, Stir bars egg-shaped, Designed specifically for round bottom Flasks and vessels. 19L x 9.5mm dia., For round-bottom Flasks sized 10, 25, 50 and 100mL, 1/EA
Biotage Magnetic Stir Bars, for 10-20 mL Microwave Reaction Vial 5/Case
Biotage Magnetic Stir Bars, for 10-20 mL Microwave Reaction Vial 5/Case
Biotage Magnetic Stir Bars, for 2-5 mL Microwave Reaction Vials 25/Case
Biotage Magnetic Stir Bars, for 2-5 mL Microwave Reaction Vials 25/Case
Cole-Parmer Micro Stir Bar, 5 mm L x 2 mm Dia; 1/Pk
Strong alnico V magnets with one-piece coating of PTFE.
Ace Glass, Inc. Stirbar, PTFE, egg shape, 25.4mmx12.7mm
25.4mm x 12.7mm egg-shaped PTFE magnetic stir bar which provides a pivot point without a separate ring or abrupt change in contour. Designed to be used with round bottom flasks and DynaBlocs.