Magnetic Stir Bars

Magnetic Stir Bars, Stirring Bars and Rods, PTFE Magnetic Stirrer Mixer Stir Bar, Magnetic Stir Bar Retriever, Magnetic stirrer with hotplate, Micro Magnetic Stirrer Bar, PTFE/ALNICO V MAGNET, standard laboratory magnetic stir bar China supplier and factory

Magnetic stir bars (aka lab stirrers) are the key accessory for magnetic stirrers. Using the strange sorcery of magnetism, stir bars rotate within the host liquid to provide safe, efficient stirring.

Manufactured from ALNICO (an alloy of aluminium, nickel, iron and cobalt) magnets encapsulated with PTFE coating. Cylindrical magnetic stirring bars offer for a wide variety of applications providing excellent mixing effect. Polished finish provides excellent centering and smooth uninterupted stirring. Their perfect contacts with the base of the flask reduce the risk of ricochet during stirring.

Magnetic stir bars

Lab stirring bars are almost always PTFE-coated. PTFE provides sufficient resistance to most of the chemicals that might require stirring.

The real variety in stirring bars are the shapes. Our selection includes the usual cylindrical / round stir bars, but also available are triangular, octagonal, egg-shaped, spin vanes, and cross-head magnetic stir bars.

The stirrer magnet is a bar magnet encapsulated in a material which protects the magnet and prevents contamination of the liquid medium.

The core of the stirrer magnet is usually Alnico V, a less used alternative is Samarium-Cobalt. Due to its exceptional chemical and thermal (-200 °C to +260 °C) properties, Polytetraflouroethylene is the most preferred encapsulant. It can easily be processed, is readily sterilised and satisfies FDA and USP Class IV requirements.

In principle, it is difficult to find the most effective magnetic stirring bar for a particular application, but important factors are the vessel shape and the viscosity of the stirring medium. In a petri dish, a long stirring bar at low speed will be effective, in a round bottom vessel egg-shaped (oval) magnetic stirrers will be a suitable choice. The ideal configuration is where the magnet of the stirring bar and the magnet of the drive are of equal length and with a minimum distance between them.

Cylindrical magnetic stirring bar » Oval or Egg-shaped magnetic stirring bar » Magnetic stirring bar with bearing neck » Magnetic stirring bar for cuvettes » Magnetic stirring bar for culture bottles » Custom manufacture for flanged reactors