PTFE Magnetic Stir Bar, 5/Pack

PTFE Magnetic Stir Bar, 5/Pack

ZHC LAB’s PTFE Magnetic Stir Bars are available in four shapes to accommodate the full range of standard laboratory vessels and stirring conditions. The Oval shape is optimized for round-bottom flasks and curved-bottom vessels, where its aerodynamic geometry promotes smooth liquid circulation and stable rotation. The Cylinder with Pivot Ring shape is designed for flat-bottom vessels; the central pivot ring stabilizes the bar against the vessel floor, reducing wobble at elevated speeds or with partially settled suspensions. The Plain Cylinder shape provides a versatile option for flat-bottom vessels when low liquid viscosity allows stable rotation without a pivot ring, and its smooth profile minimizes dead zones. The Cross (Octagonal) shape is engineered for viscous liquids and suspension applications, where its multi-lobe geometry generates higher shear forces, disperses sediment more effectively, and maintains coupling at low stirring speeds. All four shapes feature a high-purity PTFE enclosure over a strong magnetic core, providing complete chemical inertness against concentrated acids, bases, and organic solvents. Fully autoclavable and reusable. Packaged 5 per unit in a resealable protective bag.

DIMENSIONAL SPECIFICATIONS:
Oval / 8 x 20 mm (diameter x length): recommended for 10-50 mL round-bottom flasks and small vials
Oval / 10 x 30 mm (diameter x length): general-purpose, recommended for 50-250 mL round-bottom flasks
Oval / 15 x 40 mm (diameter x length): recommended for 250-500 mL round-bottom flasks and larger vessels
Cylinder with Pivot Ring / 8 x 25 mm (diameter x length): recommended for 25-100 mL beakers and flat-bottom flasks
Cylinder with Pivot Ring / 8 x 35 mm (diameter x length): general-purpose, recommended for 100-250 mL flat-bottom vessels
Cylinder with Pivot Ring / 10 x 40 mm (diameter x length): recommended for 250-500 mL beakers and larger flat-bottom containers
Plain Cylinder / 6 x 20 mm (diameter x length): recommended for low-viscosity mixing in 25-100 mL flat-bottom vessels and reagent bottles
Plain Cylinder / 8 x 30 mm (diameter x length): general-purpose, recommended for 100-250 mL flat-bottom vessels with low-viscosity liquids
Plain Cylinder / 10 x 50 mm (diameter x length): recommended for 250-1000 mL flat-bottom vessels requiring extended stirring coverage
Material: virgin PTFE encapsulation over alnico/neodymium magnetic core
Temperature range: -196deg C to +260deg C
Pack size: 5/Pack

COMMON APPLICATIONS: Magnetic stirring during chemical synthesis, reflux reactions, and solution preparation; dissolution, titration, and buffer preparation workflows; dispersion and suspension of solids and precipitates; inert atmosphere and glovebox stirring; viscous polymer, resin, or biological media mixing; pharmaceutical formulation and quality control; general chemistry, materials science, and academic laboratory use.

USAGE NOTES: Select stir bar length as approximately 1/2 to 1/3 of the vessel’s outer diameter for optimal magnetic coupling. Use the Oval shape for curved-bottom vessels; use Cylinder with Pivot Ring or Plain Cylinder for flat-bottom vessels with aqueous or low-viscosity solutions; use Cross (Octagonal) for viscous media or suspensions requiring higher shear. For viscous solutions, select a larger diameter to improve torque. Autoclave-safe at 121deg C, 15 min. Clean after use with water or appropriate solvents; avoid abrasive tools that may scratch the PTFE surface. Use a magnetic retriever wand for removal. Store away from strong external magnetic fields.