PTFE Magnetic Stir Bars with Pivot Ring — 12 to 70 mm, Pack of 10
The Globe Scientific PTFE Magnetic Stir Bars deliver smooth, low-friction mixing across general chemistry, buffer preparation, and reagent dissolution. Each bar pairs a powerful Alnico magnet core with a fully encapsulated PTFE jacket, while the molded pivot ring reduces contact area for quieter rotation and better coupling on standard magnetic stirrers.
Technical Specifications
| Product Type | Magnetic stir bar with pivot ring |
| Volume/Size | 12 mm to 70 mm length; 4.5 mm to 9.5 mm OD |
| Material | PTFE-encapsulated Alnico magnet core |
| Closure/Cap | Molded pivot ring |
| Graduation | Not applicable |
| Sterility | Non-sterile |
| Pack Size | 10 per pack |
Available Sizes
| 12 mm — Bag of 2 | SWN502 | $12.60 |
| 15 mm — Bag of 2 | SWN501 | $12.60 |
| 20 mm — Bag of 2 | SWN503 | $13.30 |
| 25 mm — Bag of 2 | SWN504 | $15.80 |
| 30 mm — Bag of 2 | SWN511 | $32.60 |
| 35 mm — Bag of 2 | SWN505 | $16.90 |
| 40 mm — Bag of 2 | SWN507 | $20.70 |
| 45 mm — Bag of 2 | SWN506 | $21.60 |
| 50 mm — Bag of 2 | SWN509 | $23.60 |
| 60 mm — Bag of 2 | SWN508 | $25.80 |
| 70 mm — Bag of 2 | SWN510 | $31.60 |
Applications
- Dissolving salts and powders during buffer and reagent preparation
- Continuous mixing in titration and pH adjustment workflows
- Sample homogenization in beakers, flasks, and media bottles
- Maintaining suspension uniformity in cell culture media prep
- Gentle agitation in heat-and-stir reactions on hotplate stirrers
- Long-bar mixing of large-volume vessels and carboys
Quality & Procurement
Stocked and shipped from US inventory by labsupplies.com, an authorized Globe Scientific dealer. Each pack carries a lot number to support traceability for CAP-, CLIA-, and ISO 15189-accredited laboratories. Institutional and grant-funded tiered pricing is available — contact our procurement team for volume quotes across multiple sizes.
Frequently Asked Questions
What is the pivot ring for?
The molded ring at the bar's center contacts the vessel floor, reducing the friction surface. This lets the bar pivot freely, couple more reliably to the drive magnet, and run quietly at both low and high speeds.
What temperature can these stir bars withstand?
PTFE encapsulation is chemically inert and tolerant of typical hotplate-stirrer temperatures. Avoid prolonged exposure near the PTFE upper limit and confirm your stirrer's plate rating for high-heat reactions.
How many stir bars come in a pack?
Each SKU is sold per pack of 10 bars of a single size. Listed prices are per pack; mix sizes across SKUs to suit different vessel volumes.
Which size should I choose for my vessel?
Match bar length to roughly two-thirds of the vessel base diameter. Shorter 12–25 mm bars suit beakers and small flasks, while 50–70 mm bars are intended for large-volume containers and carboys.