SP Bel-Art Spinbar Teflon Octagon Magnetic Stirring Bar; 38.1 x 9.5mm, White (F37110-1128)

Used for testing water alkalinity

A short magnetic bar came with the magnetic stirer, but it did not work very well. So, I ordered this longer bar and the flat-bottomed pitcher, and now I get good mixes every time.

As I progress into the lovely art of home brewing, I find that I need more and more stuff. One of those things is a stir plate to make yeast starters. I decided to got the DIY route and make my own stir plate. I purchased this spin bar to use with my setup. The magnets inside this stir bar are super strong! When used with my homemade stir plate, I can get it going quite fast. I have now used it multiple times for 24 hours or more and haven't had it thrown yet. It creates a great vortex during the stirring process. I like the larger size because it seems to stir more liquid then the smaller sizes. If you are looking for a super strong spin bar, this is the one.Pros: Durable, Very strong magnet, easy to cleanCons: I couldn't find anyIf you are also a home brewer, I bought a computer fan that had a built in speed controller. I glued some small but strong magnets to the fan and mounted it inside an old cigar box. You can find some instructions if you google cigar box stir plate. Cheers

Bought 5 of these and they all worked great at first.After a few uses, 3 of them are now spinning off center.It appears that the magnets inside have shifted so it is impossible to achieve a vortex with them any longer.I verified this by spinning them directly on a stir plate.Edit to my original 2 star review:Upon further investigation it appears that the magnets got off center because we use strong neodymium magnets to retrieve the stir bars. Was able to fix the stir bars using a strong neodymium magnet to pull the internal magnet back to center.For the price these are recommended. If you use strong magnets to retrieve the stir bars, you may offset the internal magnet. However, if you have strong magnets available they are relatively easy to fix.

It's a magnetic stir bar that said it was 1". Good news, it's magnetic and it is indeed 1".The bar certainly gets the starter going quickly but as others have noted, the center rivet makes a clinking sound that will go on for as long as you have the stir plate on. I am not sure if this design had anything to do with the nice vortex I got with my stir plate on the lowest speed, but it certainly does make the noise people wrote about. It doesn't bug me but I will likely find a replacement just in case I lose this one and compare the two. I can't knock off a star just because I am unsure of something.My stir plate is variable speed because my computer fan (80mm) is 6v and my power source is 9v allowing me to change speeds using a rheostat.

I built a homemade stir plate for yeast starters and thought I really botched it up. I spent a good 30 minutes with my old 1" stir bar trying to get the thing to balance. When the fan spun fast enough to not stop itself due to friction, the bar would immediately throw. I thought I screwed up the balance of the magnets and was about to abandon the project and shell out the $80 for a stir plate.On a whim, I ordered this stir bar for the heck of it. WHAT A DIFFERENCE! I can actually run my stir plate at full speed (only running it with 6 volts) and the bar doesn't throw. It's currently spinning in a 5L starter and performing beautifully!

I tried these after using some cheap ones and these are far superior in quality. They are well balanced and created a nice vortex. They seem expensive for what they are, but so is everything in the scientific realm.

Works well for making yeast starters for homebrew, but it is loud due to the center ring. The ring acts as a pivot point and it constantly "tinks" on the bottom of the flask. As one other reviewer mentioned, it is a stir bar and it stirs as intended, but I will likely try and find one without the center ring. The noise is the reason for the rather than 5 stars. This is an item that is impossible to find locally for me.

Se supone que debe de medir 5.08mm y mide 3.8mm de largo.