Magnetic Stir Bar PTFE Magnetic Stirrer/Mixer Bar. Spinbar Teflon Octagon Magnetic Stirring Bar, 12 Pcs Set, White

This item work perfectly in our lab. The price is fairly good comparing to other stores. Fast shipping, good purchasing experience.

This set includes a wide range of sizes, from tiny to quite large. As an experiment, I used the smallest one in a test tube and was able to generate a whirlpool. The strongest solvent I am using right now is pure laboratory grade ethanol so I can't comment on it's resistance to stronger chemicals, but so far the bars have suffered no noticeable effects from this level of solvents.

Bringing a solution up to temperature on a hotplate in a beaker, one of the two larger bars will start to tumble instead of spin as the RPM rises. I will take that stir bar out and replace it with the other one of the exact same size from this set and immediately bring it back up to the same RPM and it will spin correctly and I can continue to raise the RPM as the solution gets hotter. If I try leaving the other bar in it will keep tumbling instead of spinning at a certain RPM no matter how much hotter (more viscus) the solution gets. This is acceptable as I am rarely mixing more than one solution at a time, even though I have to hot plate/stirrers, but the quality control wasn't the greatest on the two large bars.

Working good, different sizes for different applications. Try all @ different speeds.

I really need over an inch long for a good stir

I helped my friend order these. She is very happy with them. They are very clean and well constructed. They were only one dollar each. Great buying experience.

These work very well and they appear to be inert which is important because some of the chemistry I use is potentially corrosive. I am very pleased.

Making perfume has gotten a lot more stream lined. No more running from microwave to table and back again for heated water