16x150mm Borosilicate Glass Test Tubes with Cork Stoppers, 23ml Vol, Karter Scientific 201B1 (Pack of 10)

This was the 4th time I ordered test tubes from Amazon. Surprisedly, they were perfect test tubes, much better than I expected: clear glass, thick enough, and exact sizes as described. Highly recommend.

Fully able to heat and shape them just like Pyrex but a little easier!! The only reason these might crack a little easier than some people expect is because they are a little thinner, but that suits my needs better anyway. I find them plenty sturdy yet they are lighter and I had a reason for needing thinner walls. They ARE borosilicate! There are different ratings, like 3.3 Pyrex, which perhaps they are not (I may boil fluids in thicker ones). But they softened and bent (and even fused!) a little easier than thicker and/or 3.3 boro. If they supposedly crack so easily under slight heat how come I haven't cracked ONE after heating dry until finally melting them into sealed ampules like professional labware? These are perfect for what they are. Better than thicker, name brand Pyrex for me because they shield less, certain emissions of what I place inside, and are lighter. And super value. No scratches, nothing. And a free cardboard stand to complete my cardboard mad scientist lab motif. Seriously, even that target of criticism is perfect to hold them for me, to fill, until they are used and sent away individually! I don't drip something on my own stands and have to clean or paint them. If you use corks, use real cork for dry stuff, and feel out shaping some a bit with sandpaper. Even as cork goes it actually fresh and pliable compared to old, crumbling cork! I saved them for other bottles, another free perk! How much more can I get for so little money??

I ordered these to use as a favor and was very nervous about how they would work out due to the reviews I read here. I do agree that they could be packaged better to avoid any breakage but thankfully, I didn't have any that arrived broken. I was also nervous about putting the corks in because several reviews said the tubes would break with hardly any pressure. I was happily surprised at the quality of the tubes - they are not extremely thin as I thought they might be, and they held up very well while I corked each one. No broken tubes!! In some I even had to press a little harder than I would have liked to get the cork to go in enough, but they all held up. With a careful hand and a little twisting of the corks, I had no problems. I'm very happy with the purchase and would absolutely buy these again.

If you want test tubes of these dimensions with cork stoppers included these are certainly them, and the price is right.

Yes, these were absolutely the right size and worked out for my craft

The product is as described. It is also very fragile. Although they came decently packed in paper (maybe it should have been bubble wrap), one of them was broken on arrival. I bought it for Halloween display purposes. But make sure you know that they are very fragile! Not for scientific purposes: they would most likely not survive heating and not even for scientific play with an older child for a science fair. They are really dainty. If you're thinking shots, I wouldn't risk it either, they would probably not survive too much abuse and washing either.

I did not buy these for lab purposes, but in my use case, they are great quality. I did drop one on a concrete floor and it didn't break, so I trust that these are tough borosilicate glass. I also don't see any manufacturing deviation between tubes. They are all identical, if that matters to you.

Good

I got one extra tube and 13 extra corks! I broke the extra tube trying to cork it too hard so I guess I got exactly what was ordered ;)

Just what I needed. TY

The best partner for an ants farmer. I bought it for me and my brother as we really like ants and it's the best way to start a colony. I was expecting it to be made of cheap glass looking plastic but turns out it was good quality glass. I'm very satisfied by this product and will certainly buy it again.

Buen vendedor aún cuando el producto era muy delicado todos los tubos llegaron en perfecto estado y a tiempo. Lo recomiendo 100%

Good quality glass tubes