SP Bel-Art Circulus Teflon Magnetic Stirring Bar; 36mm Length, White (F37170-0000)...

For some reason, this spin bar never centers. Its pretty frustrating. And the seams on the bar are hard to ensure stay clean. I was having trouble getting the bar to spin consistently. I spent about 20 mins trying to center everything and switched vessels. Eventually I tried it without a container, just on the spin plate. It still wouldnt spin. The bar is weighted wrong, it isnt balanced.

Worst spinbar I have ever used... DO NOT BUY

I'm fairly disappointed with this, considering the price. For as much as it cost it should have been really nice and it isn't. I worry that it will not clean easily, thereby risking contamination from one use to the next. Stirbars are supposed to be impervious to contamination, and this one won't be. Pros: It is pretty heavy, spins well on my stir plate, makes a very good vortex, and is very quiet. Overall, i think the shape is a good one. Cons: Altho the packaging clearly states it is "seamless" it isn't. There are ridges on the bar that appear to be where the seams were ground down, and this has left jagged bumps and indentations. Further, where the center bar / axel joins with the side discs, there is a clear gap / seam. Obviously this started as three pieces, but they were coated individually then assembled so there is no coating covering the areas where the pieces meet. Not a big deal...? Well, this will allow fluids and gunk to build up in the gap, so anything from one time it's used might end up in whatever it stirs the next time. Of particular concern is the risk of bacteria living in the hard to clean seams and causing contamination. I am keeping it because I don't have time for the hassle of returning it and because it does stir well, but I'm not looking forward to the extra work cleaning it between uses. I wouldn't buy it again, especially at the price, and I advise you to look elsewhere.