PTFE Magnetic Stir Bars, A / B / C / D Types
White PTFE-encapsulated permanent magnetic stir bars for laboratory mixing, chemical processing and industrial stirring. Select the exact shape and nominal diameter x length for your vessel and stirrer. This listing offers 113 dimensioned A, B, C and D configurations. Vessels, stirrers and other shapes shown in supplier material are not included.
Shape selection
- A: Olive / oval shape, generally selected for round-bottom vessels.
- B: Cylindrical bar with a pivot ring, generally selected for flat-bottom vessels.
- C: Straight cylindrical bar, described for lower-concentration liquids in round containers with uneven flat bases.
- D: Full cylindrical bar for flat- or round-bottom vessels where stable stirring is needed.
Material and use
The outer shell is polytetrafluoroethylene (PTFE / F4), with a permanent magnet inside. PTFE provides a smooth, low-friction, low-adhesion surface and resistance to many chemical reagents and solvents. Confirm compatibility with the actual chemical, concentration and operating conditions. The supplier describes low-temperature toughness and approximately 5% elongation retention, without a stated test temperature or method.
Applications described by the supplier include liquid or powder mixing in laboratory, chemical, industrial and metallurgical work. Suitability depends on your vessel, mixture, magnetic stirrer and operating conditions.
Gauss values on model images are supplier-stated reference values, not independently verified measurements.
Important precautions
- Do not use for prolonged periods at 200°C or above: the internal magnet may lose magnetism. PTFE shell properties alone are not a temperature rating for the complete stir bar.
- Supplier selection guideline: bar length about one-third to one-half of the vessel outside diameter. Thicker mixtures may require a larger bar diameter. Verify internal clearance and stable magnetic coupling.
- All dimensions are nominal. The supplier reports manual-measurement variation of 1–3 mm; confirm critical fit before use.
- Color may vary slightly with lighting and display settings. The product is white, with original photographic shadows preserved.
Reading the model before ordering
The A, B, C and D prefixes identify the shape families listed above. Read the nominal diameter and length together with the selected photograph and approximate inch dimensions; the model prefix alone does not establish a replacement match.
For example, this range's A10 x 25 mm model is not the same size as A10 in the separate high-temperature series, which is listed as 6 x 10 mm. Confirm the complete size and series, not just the A-number.
Compare other PTFE stir bar listings
- Cross, H-series, eight-tooth, spherical and cylindrical models in 2-piece packs.
- Supplier-designated high-temperature series: 17 models — confirm the complete assembly's operating limit before use.
- Seven cylindrical D sizes with model-specific pack quantities.
Available sizes, vessel examples and real product views
