Laboy Single-Neck Round-Bottom Flask, 250mL, 24/40 Outer Joint

By strange size, I mean the diameter is slightly smaller than 1L RBFs I've gotten from other manufacturers. They all fit my 1L heating mantle nice and snug -- this flask has a small amount of space between the mantle and flask when it rests on the bottom (~5-7mm at the top of the mantle). I just made some padding out of aluminum foil and it worked fine (still has a 1L volume, somehow?) In fact, this is the first 1L RBF I've purchased from Amazon that didn't break or even show any signs of cracking after distilling a molten mixture of NaHSO4 and NaNO3 to produce fuming nitric acid! I've run the process twice now in the Laboy flask with no visible damage whatsoever. Thank God! Previously, the flasks would crack, spilling a mixture of nitric, sulfuric, and molten sodium bisulfate all over the heating mantle, not only ruining the distillation but setting me back ~$200 to replace the flask and mantle - closer to 500 the first time, as i was using my nice, fancy mantle... RIP :( I debated naming any of the other flask brands that failed me, as I didn't want to step on any toes, but since it was such a very expensive and extremely hazardous failure, I will. DO NOT USE RBFs FROM VEVOR, YUXun, QINGYI, OR DESCHEM. At least not for anything but the mildest of heating/distillation processes! Laboy continues to impress. Spend the few extra bucks - it will save you a fortune down the road, not to mention a lengthy and hazardous cleanup. 5/5, will be buying more.

Thanks!

I recall when breaking glass labware meant an annoying bill from the store room manager, so I was dubious about the quality of chemical glassware coming from China for such low prices. Laboy exceeds my expectations--the glass is of a durable thickness, without ripples or "seeds" or inclusions, the ground glass mates perfectly with my American-made glassware (the grind seems a bit more coarse but to no disadvantage) and even though I haven't stress tested the flask (e.g., pouring liquid nitrogen into a flask at red heat--jeez, just kidding) I have full confidence that Laboy glassware will perform under normal lab conditions to the highest standards.

I tend to order SEOH and Laboy most often for a majority of my experiments and products... Laboy isn't what you have probably come expect from a Chinese manufacturer. If you need glassware that just looks and feels like awesome quality--the answer is Laboy.. I love Laboy for their quality. When I need something that I expect to break like beakers I tend to get SEOH (their prices are excellent), but when I get something with the expectation of it lasting a lot of abuse then Laboy is absolutely the way to go. It's worth it to spend a little more on some things this flask is definitely one of those items.

Laboy makes a lot of great quality glass and this is no exception. Thick glass and very symmetrical. However it wasn't quite 1000ml. But I only put about 600ml of liquid to boil at max, so i suppose it doesn't matter too much.

It took a little longer than I expected for these to arrive, but they seem quite nice. The only thing I've done so far is check the fit with my heating mantle and they are slightly under size. That isn't a big deal in my case - the actual total volume doesn't have to be exact and they do vary between manufacturers. If I can remember to do so, I'll update my review with the actual dimensions. update: the measurement is a little tricky - my calipers don't have jaws that reach far enough to make it to the center diameter, so I had to find a different way to do it. I got 3.960 inches (100.6mm) for the largest diameter.

Excellent boiling flask. Strong and durable. The product takes a few weeks to arrive, but is well worth the wait. order due to lab timer failing, and stir plate remaining on. The boiling flask maintained shape, and spider web cracked after the stir bar melted. No liquid came in contact with the sir plate. Excellent, and SAFE product. Any product LABOY can be guaranteed to meet your organic chemistry needs.

I use these for vacuum distillations. The ground glass joint is nearly perfect for all of the flasks that arrived as far as I can tell. They are the right size and their weights deviate from each other but not by too much. It's hard to beat quality labware for this price! Thomas

Very good for the price. It will do the job just fine.

quality product at a good price with speedy service ! It"s hard to complain about anything !!!!!! Thanks for the quality service!

it came exactly 1.5 months after ordering, which was the limit date before I could ask for a refund. The glassblowing is excellent, comparable to VWR pieces I've bought in the past for 4x the price. Shipping is the only problem. How does it take 34 days from the Chinese border to the Canadian border is unbelievable considering shipping isn't free. they should really get a better shipping company. glass is great but I won't be ordering again, this is just way too slow

The round-bottom flask has thicker glass for rugged use. It works well and the quality is good.

As described. Well packaged as it obviously spent time off road.