Tips for Selecting the Ideal Magnetic Stirring Bar

When it comes to expediting experiments and streamlining commercial production of cannabis-based solutions, few devices have altered the laboratory landscape to the extend of magnetic stirrers. These compact and efficient pieces of equipment effortlessly combine ingredients so researchers may swiftly identify optimum processing procedures.

The ability to control stirring speed – with or without heat application – researchers are given a unique chance to swiftly experiment with compounds. This simple act is responsible for some of the greatest product and medicine innovations throughout the cannabis industry. Although it’s easy to look at the device as a cohesive unit, perhaps the greatest element is also one of the smallest: the magnetic stirring bar.

A Flea You’ll Love | Magnetic Stirring Bar Operation

Lovingly referred to as a “flea,” magnetic stirring bars play a vitally important role when it comes to the actual mixing process. In fact, without this relatively compact accessory, magnetic stirrers wouldn’t exist. Before we get into how to select your ideal magnetic stirring bar, let’s briefly explore how they work.

In a standard benchtop magnetic stirrer, there are two primary elements: the base and the beaker – or flask. The base houses not only the control panel, but also an internal rotating magnet. The beaker is then placed on the base and the magnetic stirring bar is placed in the liquid solution.

When activated, the internal magnet begins to spin. The magnetic energy created by the spinning magnet is then transferred to the flea, which causes it to spin at a similar speed. Now that we have a basic explanation of a stirring bar, let’s delve into the elements that shape your purchasing decision.

The Three Pillars of Magnetic Stirring Bars

Although we could delve into the many different uses of specific stirring bars, all of this information can be boiled down into three pillars: Length, Shape and Composition. These are the primary criteria you must consider when selecting the ideal flea for a specific experiment.

● Length | It’s common knowledge that magnets are attracted to opposite magnetic poles. That is to say, the “north” pole of a magnet is attracted to the “south” pole of another magnet. If you were to place two “north” portions of a magnet together, you’d feel a strong magnetic repulsion. When it comes to magnetic stirring bars, the length of the internal rotating magnet must match the length of the flea.

● Shape | The actual geometrical shape of the stirring bar can either negatively or positively influence immersion efficiency. There are many different stir bar shapes, which are best suited for specific type of solutions. For example, when you use a round bottom flask, which is the ideal flask for some hotplate magnetic stirrers, a straight bar stirring magnet bar would not be the most efficient option.

● Composition | Contamination is a major concern for many laboratories. This is especially important when you’re placing a foreign object into a sensitive liquid solution. Magnetic stirring bars are typically made out of one of three coatings: Teflon, Pyrex Glass and Plastic. The latter is typically best-suited for abrasive samples while a samarium cobalt magnet is generally recommended when stirring viscous solutions at high speeds. Regardless, all coatings must be FDA approved.

Need additional information or assistance? Don’t hesitate to Ask Us A Question and our magnetic stirring bar professionals will swiftly come to your assistance.


CAT Scientific


  1. Dudu Light on September 4, 2016 at 12:41 am

    I make colloidal water using 2 99.99% rods suspended in a glass bottle held by positive and negative clips. The small magnetic rod is placed at the bottom of the bottle, when plugged in the rod spins to distributes the silver ions evenly. Not sure what size magnetic stirrer I need. Thank you.

  2. G Abbas Scientific on January 12, 2017 at 11:03 pm

    A lot of thanks for this brilliant post

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