There are stirring bars designed specifically for use in lab applications such as those requiring high chemical resistance, zero absorption or high heat. Popular stir bar options are:
- chemical resistant Teflon® PTFE
- high temperature Pyrex® glass
- small size Flea Micro® for vials and test tubes
Chemically Resistant Teflon® PTFE:
Sized from 1-1/2 x 5/16" to 3" x 1/2", these stir bars are octagonal to maximize the stirring surface and have molded-in pivot rings for stirring efficiency.
The chemical resistant Teflon® PTFE coating makes them suitable for use in a variety of substances and the four available colors (white, red, yellow, blue) allow for easy identification and segregation.
High Temperature Pyrex®: coated round SpinBar® stir bars are very effective at high temperatures all the way up to 274C (525F) because the internal magnet is enclosed in a thick layer of Pyrex® glass.
These stir bars are ideal for ‘zero absorption’ stirring applications, and the glass surface is completely smooth, making these stir bars very easy to clean. The characteristic low expansion of Pyrex® glass makes it suitable for a range of temperatures. Available in four sizes from 1/2" to 1-1/2" long.
Flea Micro® Stir Bars: These tiny, efficient stir bars are ideal for vials, test tubes and centrifuge tube mixing.
Available in a variety of lengths, they range from 0.15mm thick to about 3mm thick, and from 2mm to 12.7mm long.
and feature a chemically resistant Teflon® PTFE coating, ALNICO V coated magnet, and a variety of color options including white, red, yellow or blue.
(Click to enlarge the graphic, which shows the approximate shape and relative size of the various stir bars, and the photograph illustrates the color and appearance of selected items.)