SP Bel-Art Spinplus Teflon Magnetic Stirring Bar; 9.5 x 4.7mm, White (F37144-0038)

I use this when I'm making yeast starters for home brewing, which doesn't really require any crazy speeds on my stir plate - just enough to make a vortex. Even then, most of the time my traditional stir bars would get thrown so very easy. Nothing worse than waking up in the morning to find that your starter (probably) hasn't been spinning all night.With this one, I almost never have to worry about it getting thrown. Once it's lined up and spinning, it's rock solid. As a bonus, I don't need as much speed to create a vortex either. It's the only stir bar I use any more. Seriously, why are you still reading? Buy this one, it's awesome!

I use this for making yeast starters while homebrewing. I own a professional-grade stir plate, and both 1000ml and 2000ml erlenmeyer flasks. The bar spins fairly well and produces a decent vortex; anecdotally, it may be a stronger vortex than a regular stir bar. However, unlike a flat stir bar of similar length, however, this one appears to be more prone to "throwing" at high speeds. I was able to get it to operate sufficiently at about 75-80% of the stir plate's maximum setting.

I'm comparing this unit with the Bel-Art Octagonal Spinbar, and another magnet that was very similar to the Spinbar that came with my magnetic stirrer. In water this Cross produces the best vortex. For my application, I'm stirring a very thick fluid, and this unit tracks my magnetic stirrer machine better than the other two. I have purchased 3 more of these, because they work the best in my application.

I use this exclusively for yeast starter for home brew and it works perfectly for that purpose. In 800ml of liquid within a 2000ml Erlenmeyer flask, the liquid comes just a bit above the stir bar. At less than half power on my stir plate, a quarter-sized vortex is created that sucks the liquid below the top of the stir bar. I've used this stir bar eight times for 18-24 hours at a time and it has not been thrown once. It's much better than the pill-shaped bar that came with my unit.

I use this stir bar to mix small dye samples for hand dyeing. It fits nicely into 100 ml beakers and at slower speeds does not spill liquids over the sides. The angles arms of the stirbar lift the products on the bottom of the vessel into the bulk of the liquid and reliably mix it well. It is small for mixing large volumes like 1 liter or so, but can mix a vortex at that volume, but as the thickness of the liquid increases, one's desire to increase speed to keep the mixing process going can make the stirbar unstable and go skittering off center.I find this reliable to mix up to 500 ml, but over that I use a larger straight triangular stir bar for volumes up to 2 liters.

The stirrer performs well at lower RPM, but I did not see any improvement in stability at higher RPM compared to a stirrer bar.An octagonal stirrer bar 50x8mm from Fisher labs managed to stay in sync at higher RPM.Nonetheless if you don't care about running it at high RPM, then you can expect to see a nice vortex.

I couldn't get this to spin much faster than 500 RPM without it flying off center. The cross design seemed like it would be effective, and it is effective at lower speeds, but anything faster than 500 RPM and it flies off center.Edit:After testing a regular shaped spin bar with this one, I've decided that it works really well by comparison. With the non cross shaped stir bar I couldn't get a vortex going, but with this one I can get a vortex. As long as you keep it below 500 RPM it produces a nice vortex. With the rod shaped stir bar it wouldn't go more than 300 RPM and would not produce a vortex.

This stir bar lays flat, and unlike most regular spin bars, this one does not have a raised nub in the center. As a result, friction of the cross's arms scraping the bottom causes it to spin out and it is immediately thrown. I have tried this at various speeds and with different Erlenmeyer flasks. The result is always the same. 13 bucks for an unusable spin bar is a waste.

Esperaba que mezclara mejor que uno convencional en forma de cápsula, pero no fue así.Se desorbita muy fácil en velocidades muy bajas aún y cuando el líquido sea agua pura.

Good variety of stir magnets