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Bel-Art F37112-0001 Disposable Polygon Spinbar Magnetic Alnico Stirring Bars; Teflon Coated, 25.4 x 8 mm (Pack of 100)

Price: $154.45 & FREE Shipping. Details
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1 x 5/16"(25.4 x 8 mm)
  • Enter your model number above to make sure this fits.
  • Polygonal shape is smoother than an octagonal shape and creates more turbulence and a stronger vortex than a round, cylindrical shape
  • Teflon (PTFE) casing is chemically inert, can be used with corrosive chemicals, and helps reduce friction and wear while spinning
  • Smooth surface provides quicker cleanup and less risk of cross-contamination than bars with pivot rings and allows the bar to spin on the bottom of the container to disperse light sediment and air bubbles
  • Internal magnet made from alnico V, an alloy of aluminum, nickel, iron, and cobalt
  • Single-use stir bar can be disposed of after working with hazardous substances or when contamination is a concern
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$154.45 & FREE Shipping. Details Usually ships within 1 to 2 months. Ships from and sold by

Product Description

Size:1 x 5/16"(25.4 x 8 mm)

Stirring Bar, PTFE Material, PTFE Coating, Polygon Shape, Size 1 x 5/16 In., White, Package Quantity 100 Technical Specification Item Stirring Bar Material PTFE Coating PTFE Shape Polygon Size 1 x 5/16 Color White

Product Information

Size: 1 x 5/16"(25.4 x 8 mm)
Technical Details
Brand NameBel-Art Products
Item Weight12.8 ounces
Product Dimensions4.9 x 3.5 x 1 inches
Item model number371120001
Material TypePTFE (Polytetrafluoroethylene)
Number of Items100
Size1 x 5/16"(25.4 x 8 mm)
Manufacturer Part Number371120001
Additional Information
Best Sellers Rank #67,347 in Office Products (See top 100)
Shipping Weight12.8 ounces (View shipping rates and policies)
Domestic Shipping Item can be shipped within U.S.
International Shipping This item can be shipped to select countries outside of the U.S. Learn More
Date First AvailableNovember 3, 2009
Warranty & Support

Manufacturer’s warranty can be requested from customer service. Click here to make a request to customer service.
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From the Manufacturer

disposable magnetic stirbar, disposable magnetic stirrer

Disposable Polygon Spinbar Magnetic Stir Bars

Disposable Polygon Spinbar Magnetic Stir Bars

The multifaceted magnetic stirring bar surface adds turbulence relative to similar size smooth cylindrical stirring bars.

  • Ideal for single use applications mixing radioactive reagents or when cross contamination might be a concern
  • Alnico magnet encapsulated in FDA Grade, USP Class VI PTFE low friction coating; durable and inert
  • Manufactured in a registered ISO 9001:2008, as verified by SGS certification
  • Autoclavable
magnetic stirbars, magnetic stirring, magnetics spin bars

Magnetic Stirring

Magnetic Stirring Bar Selection & Use

Magnetic stirring is used in a number of common laboratory procedures, yet the importance of selecting the best stirring bar for each particular application is often overlooked. The drive magnet, vessel shape, viscosity and abrasiveness of the materials should all be considered when choosing the size, shape and materials (coating and magnet) of the magnetic stirring bar in order to achieve effective, efficient stirring results.

First, let’s discuss magnetism. On the most basic level, we know that opposite poles attract. A magnetic stirrer has a drive magnet, generally a bar or U-shape made of a metallic alloy or a ceramic which rotates powered by a drive motor. The magnetic poles of the drive magnet are typically about two inches apart in bench top models, and can be up to six inches apart in larger units used to mix 50 gallons of liquid solution. For optimum magnetic coupling the distance between the magnetic poles of the drive magnet and the length of the stirring bar should be equal. Bars too long or too short in proportion to the drive magnet will not have optimum coupling which is important to reduce spinout.

Once a magnetic stirring bar has been placed in a container with solution, it should be positioned directly over the center of the drive magnet. The stirring speed should be increased slowly, until the desired vortex pattern is achieved. Should the magnetic stirring bar lose its coupling with the drive magnet because of the speed of the drive magnet, viscosity of the fluid, or an improperly selected stirring bar length, it is said to have 'spun-out.'

Vertical distance between the drive magnet and the stirring bar should be kept to a minimum for the best coupling and stirring efficiency. Therefore, the containing vessel should be as thin as practical.

The selection of the shape of the magnetic stirring bar also influences the resulting vortex in that multi-sided shapes may be more efficient in moving solutions and certain shapes have been designed to provide a tailored fit in specialty vessels such as test tubes, cuvettes and spectrophotometer cells.

Magnetic stirring bars are generally made of ALNICO (an alloy of aluminum, nickel, iron and cobalt) magnets encapsulated in an FDA approved PTFE coating. In addition, magnetic stirring bars also use high energy magnetic materials, such as Samarium Cobalt which increases strength of coupling with a drive magnet and helps to reduce spinout when mixing viscous solutions or mixing at high speeds.

Newer to the market, the Bel-Art Products Spinfinity magnetic stirring bars use ALNICO magnets encapsulated in plastic for increased durability in granular slurries.

Use for General Stirring Applications Use for High Temperature Stirring Applications Use for Viscous Solutions High Speed Stirring Applications Use for Abrasive Slurries Extended Stirring Applications
Brand / Type Spinbar Teflon PTFE Spinbar Pyrex Glass Spinbar Rare Earth Samarium Cobalt Spinfinity
Magnetic Type Alnico Alnico Samarium Cobalt Alnico
Covering Teflon PTFE Clear Pyrex Glass Teflon PTFE Plastic
Features / Benefits Wide selection of shapes and sizes to fit vessels of all types; Individual shapes create different vortexes for efficient and effective stirring Heated stirring applications up to 274°C (525°F) Reliable Magnetic Coupling – Superior magnetic energy reduces frequency of spinout in the most vigorous applications Durable – Last 2.5 to 3 times longer under conditions known to traditionally cause material breakdown
FDA grade Teflon PTFE low friction coating is durable and inert Glass casing has zero absorption and porosity FDA Grade Teflon PTFE low friction coating is durable and inert Outer shell made from FDA approved materials
Color selection for color-coding work processes Distinct Color – Green color lets you quickly identify Spinbar Rare Earth Samarium Cobalt Distinct Color – Quickly identify the Spinfinity difference by its purple color

Technical Details

Size: 1 x 5/16"(25.4 x 8 mm)
  • Brand Name: Bel-Art Products
  • Part Number: 371120001
  • Material Type: PTFE (Polytetrafluoroethylene)
  • Number of Items: 100
  • Item Package Quantity: 1

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