How to Choose a Laboratory Stirrer: 2026 Buying Guide
How to Choose a Laboratory Stirrer: 2026 Buying Guide
The right stirrer depends on how much your sample resists mixing. Choosing comes down to three decisions: overhead vs magnetic, the speed/torque your viscosity demands, and whether you need integrated heating. This guide maps each to the Yamato Scientific LR, LT, MFD, MFH, and MG stirrers.
1. Overhead or magnetic?
- Overhead (LR / LT) — a motor-driven shaft and propeller for larger volumes and high-viscosity fluids a stir bar can't move: resins, gels, slurries, big beakers.
- Magnetic (MFD / MFH / MG) — a spinning stir bar for low-to-medium-viscosity liquids in closed or sterile vessels. The MFD's strong field keeps stirring even when the flask is lifted off the plate.
2. Match speed and torque to viscosity (overhead)
| Model | Speed | Torque | Viscosity |
|---|---|---|---|
| LT-400A | 10–300 rpm | 0.9 N·m | High |
| LT-400B | 15–600 rpm | 0.5 N·m | Medium |
| LT-400C | 25–1200 rpm | 0.3 N·m | Medium-low |
| LT-500A | 15–600 rpm | 1.0 N·m | High |
| LT-500B | 25–1200 rpm | 0.6 N·m | Medium |
| LR-500A | 34–340 rpm | 1.96 N·m | Very high |
| LR-500B | 100–1000 rpm | 0.98 N·m | High |
All use a gearless direct-drive DC brushless motor with speed-feedback control, digital display, and torque/overload indicator. Buy the main body, or a complete set with stand, rod, and stainless shaft.
3. Do you need heating — and how many positions?
- Stir only — MFD-800 (50–1600 rpm, up to 20 L).
- Stir + heat — MFH-800 adds a PID hot plate to 310°C.
- Parallel reactions — MG-600H gives six individually controlled stir-and-heat positions (to 250°C).
The MFD and MFH seat into Yamato BOG/BOS oil baths for higher-temperature work.
Frequently Asked Questions
When should I use an overhead stirrer instead of a magnetic one?
Use overhead for large volumes and high-viscosity samples where a stir bar can't generate enough force; use magnetic for low-to-medium-viscosity liquids in closed or sterile vessels.
How do I pick the right overhead model?
Match torque to viscosity: higher torque (LR-500A, 1.96 N·m) for thick fluids, higher speed (LT-400C/500B, to 1200 rpm) for thin ones.
What is stirrer-detachment detection?
On the MFD/MFH, the magnetic field is strong enough to keep stirring even if the flask lifts off the plate; the function alerts you to the condition.
Can I use a magnetic stirrer with an oil bath?
Yes — the MFD-800 and MFH-800 pair with Yamato BOG and BOS oil baths, which seat the plate to prevent slipping.
Source: Yamato Scientific LR/LT, MFD, MFH, MG documentation. LabSupplies.com is an authorized Yamato dealer — genuine units, full manufacturer warranty, in stock, ships from USA.