2pcs Lab Borosilicate Glass 250ML Separating Funnel Heavy Wall Conical Separatory Funnel with 24/40 Joints and PTFE Stopcock，2 Sets

These are pretty good separatory funnels. The glass is reasonably thick and they came without any cracks or anything like that. Having such small funnels is very useful when doing chemistry projects and you get down to using small amounts of whatever chemical you are working with. The small funnel makes it easy to not lose anything to the sides of the funnel like with a larger funnel. The stoppers are glass on glass which is nice and they fit snugly and the stopcock didn't have any leaks in my testing. For the price, I am happy with these separatory funnels, 5 stars!

I got my PhD in organic chemistry and teach chemistry at the college level, so I have used many seperatory funnels in my time. I decided to get a set for some at home projects and was attracted to the low cost on these (ones I've purchased for lab have been over $100 a piece). Funnels arrived in good shape, no signs of cracks or breaks, in tight fitting thick Styrofoam. Filled them with water to test sealing and even with a few inversions no leaks, once I dialed in the correct tightness on the stopcock (see comment below)My reservations come from two things. First the stoppers are clearly not up to the same standard as ones I've used in lab. They are uneven and the bottoms show signs of breaks where the ground glass is not present. This doesn't impact the utility in the slightest, but most of the ones I have used are even with a slight chamfer around the base. Sloppiness like this always makes me worry where else they've cut corners. Second the gasket ring for tightening isn't as sturdy as normal. In order to tighten this to the degree needed to keep leaks from occurring at the stopcock, I needed to have it bulging out from the sides. Normally this wouldn't happen because it would be a stiffer material. I've known these to wear out but not until long use in the lab, with these I feel less certain.In the end, for the price, this is probably worth it you're not handling anything to dangerous and just need something cheap to get by with or to test out. For more involved use you might want to invest a bit more

From the moment I started using these separating funnels, I could tell they were built to last. The glass was clear and sturdy, and the seals on both ends fit perfectly without any issues. It’s always reassuring when something just works without needing adjustments, and these gave me that feeling right away.The stopcocks turned smoothly, and I didn’t have to deal with any leaks, which can be a common problem with other setups. Everything stayed clean and secure, and I was able to go about my work without distractions. I appreciated how easy it was to control the flow without second-guessing if something might go wrong.Cleaning them afterward was just as straightforward. The heavy walls of the glass made me feel confident they wouldn’t easily break, but they weren’t overly bulky either. Overall, they’ve integrated into my routine without a hitch, and I feel comfortable reaching for them every time.

I have been using a pipette to separate fluids for a while and it was nice to snag one of these. These work as well as the ones I remember using in chem class. The stopcocks turn easily and don't leak and the shape of the funnel makes it easy to not only separate liquids but see what you're doing.

Not much needs to be said. The joints mate well to my other glass, the actuation on the valve is smooth and adjusts well, there are no chips and it's holding up well. The only shortcomings are thin packaging materials and the print quality on the glass is low. I'll continue using these as there's nothing wrong with them.

Grabbed this guys since I just needed a means to drop acid into a controlled environment for a project. Definitely great quality and packaged very well for shipping borosilicate (a lot of chemistry components aren't supported well). Only needed 1, but it was a great price for 2, and I can always use more equipment with this growing hobby of mine. The only let down was the joint size (since the rest of my equipment is 24/40) but it performs great. I always test this components out the box by pulling a vacuum and making sure the stopcock functions and there are no misshapen joints (had that mistake happen to me once before). These held the vacuum and will be a great asset for my growing chemistry equipment.

These are fairly typical laboratory separatory funnels. The glass stopcock fits snug. The PTFE stopcock at the bottom also fits snug, but can be loosened with the hand-screw for ease of adjusting flow, or tightened to lock it down.When I worked in a laboratory I used these every day. Now I ordered these for use at home; I sometimes make tinctures or liqueurs, and it can be difficult to filter out all of the fine sediment. In time most sediment will settle, but it can be difficult to decant the clear liquid from the sediment layer using regular liquor decanters. These funnels are made to order. The PTFE stopcock is perfect as it will allow the liquid to settle for a long time without leaking.You will need your own stand for these- although it is easy to rig something makeshift. A simple vase of appropriate size will suffice.

It came in good working condition and not broken. So many times I am afraid to buy borosilicate glass for my lab in fears it’s cheap and broken. It is perfect weight and thickness. Works great!