16X150mm Glass Test Tubes with Rubber Stoppers, Karter Scientific 201B5 (Pack of 10)

Thin, brittle glass test tubes. They do not tolerate the stopper being pressed in with even moderate pressure---the tops on about 1/3 of them broke when the stopper was pressed in. Even when handled with care, too many of them broke.I ordered these in a pinch because I needed them in a hurry. They worked, (because I ordered extras) but I wound up having throw away so many broken ones that I would not order them again. If you need to heat or stopper the tubes, then you will need to look elsewhere for sturdier ones.

Needed these for a last minute in-home science project for college, and they arrived in perfect condition. Also keep in mind that my project does not require the tubes being under any sort of heat, which is why I did not need a fancy borosilicate based test tubes. At first, I thought it was only one, but saw that it was a set of 5, which made me feel better for the price I paid. Also, to note, this was the perfect replacement to the 25x150 mm that i originally needed, as 200 mm exceeds 150 mm. All tubes come with their own caps, and I would recommend this to other people looking for a cheap but good quality set of glass test tubes!

I ordered these test tubes so I could use them as bud vases. I drill holes in wood and then insert the test tubes into the holes so people can use them as bud vases or small spice racks. So here are the issues I've had with this product:1. Dreadful packaging - it is as if someone just grabs a handful and then throws them in the box w/ wadded up paper around them. Needless to say, one was cracked on arrival. Amazon was kind enough to refund 10% back to me for the broken item.2. Glass is very fragile and easily broken3. The aren't consistent diameters - I drill holes in wood with a forstner bit on a drill press and some of the tubes fit in the hole and some don't - this tells me that they are inconsistent diameters (read: poor quality control)4. Rubber stoppers don't fit - I have to muscle it in and it only goes in about 1/32 of an inch - too scared to force it any further based on fragile glass.Anyhow, these things are trash. Look for a different product/manufacturer.

I received my tubes this morning an already had one explode on me when heated. Most of the tubes have stress cracks around the top edge, which is also very far from flat. Very inconsistent quality control. Packaging was terrible, I'm surprised they all made it in one piece.They may be a bit cheaper, but next time I'll pay extra to get tubes made by Pyrex. Not all borosilicate is the same!Bottom line: Buy them if you want to save a buck and don't intend to use them in a lab setting, especially if you need to heat them.

The tubes are okay....., they are glass tubes. However, the stoppers are another story. First, they are the wrong size. It is as if they just grabbed a hand full of stoppers out of the nearest box of stoppers. The narrowest part of the stopper is bigger than the test tube opening. You have to really work to get one in the tube at all. You have to apply so much pressure, I'm afraid I will break the tube. Secondly, The rubber reacts with the liquid I am using. I am using essential perfume oils. The rubber gets all soft and starts to break down getting black stuff all over whatever touches the part that got wet. If you get it on your hands, you will have to use soap and water and a lot of scrubbing to get it off.So, I recommend against these. Buy something else.

1. NOT PYREX! No Pyrex Marketing on the tubes alone tells you that.2. NOT Even Borosilicate Glass (Unbranded Pyrex)3. No tube lip4, Shatters EXACTLY like you would expect if you took a light bulb and put it over a bunson burner!

They are great, but these caps were NOT made for these tubes. You can BARELY get the stopper in the tube at all, not even close to about half way to seal like the higher quality ones.The redeeming features are the price and they are actually pyrex.I am on the fence if I would buy again.

Seems rather poorly packaged, like 10 of these were jammed into a box that didn't quite have enough room..True to that, I guess there was only room for 9, as only 9 of them were intact when i opened the package.Not going to bother with trying to return these, as 9/10 were intact and it's not worth the hassle.

Test tubes arrived on time. However, it is not made of Pyrex glass. My son tried to do the invisible test tube experiment with these test tubes & Wesson oil. No luck with these test tubes. Greatly disappointed. Good thing we have back up plan and use our Pyrex measuring cups and did the experiment successfully without any issue. I wonder if I can get a refund from the company?

Laboratoire

Good

Fast delivery, very good quality, just as described, excellent packaging

The stoppers included were too big for the tubes.