Pyrex used to exist entirely for the purpose of being a recognizable brand of borosilicate glass. Soda-lime Pyrex is the Pyrex company trying to scam us.
It used to be borosilicate they one day stopped using it to make more profits. My dad still has a old bake dish and when he makes roasts he will put it on a gas burner and make gravy never once had a shatter can't say the same for modern glass ware from them
Plus heated the Pyrex kitchen up with consistent heat and on the pyrex beaker he was moving the heat back and forth therefore the heat was more focused on the kitchen and not as much on the beaker if he would have kept the heat as consistent the beaker would have done the same as kitchen pyrex
The lab product was also thinner than the kitchen measuring cup. I NEVER had a PYREX (borosilicate glass) shatter. It definitely has been put under mechanical stress also.
@@willzander6514 cool. Pray that your glass continues workin then? Idk what you want from the dude. He tested them. 1 sucks the other doesn’t. And just cause it turns out to be the “good Pyrex” doesn’t mean it can’t shatter from heat 😂
This is why old Pyrex dishware is valued so highly; all Pyrex used to be made of borosilicate until they swapped the kitchenware to cheaper soda lime glass.
It's not that valuable. You can just buy it new from Europe (and I'm sure many other places) where it's still made with borosilicate. If you want an easy way to tell if modern Pyrex is borosilicate, check where it's made. If it's made in France it'll be borosilicate.
@@lost4468yt "valued" and "valuable" are two different concepts imo. they made an entire show on this contrasting premise via "pawn stars". plenty of folks brought in highly valued family heirlooms that simply weren't worth much of anything other than a "great" tv moment, a very questionable value if you ask me lol.
@@jn1211 so does this same concept follow old barn wood? Regular wood goes for about $8 for 2x4s in my area, whereas “vintage” barn wood can sell for double or triple that.
Another note to take, Is that the *borosilicate glass beaker* is much much *thinner glass* , this is because if your glass is thicker the *Heat from your blow torch will travel on the outside of the glass* (because it thick) and the *inner wall of the glass will be at a different temp*, this causes *uneven expansion* and that can *crack/shatter the glass*, that’s way lab glass is generally thin.
This makes a lot of sense, I had not really considered why most common glassware is fairly thin. Expanding on this all the thicker glassware that I've ever seen in a lab are those that are typically used under vacuum (negitive pressure).
It’s also worth noting there are two different companies selling glassware under the name “Pyrex”. The PYREX brand is borosilicate. The pyrex brand is soda lime
Thickness of the glass is also a huge factor, thermal expansion of glass is the issue causing the shattering, borosilicate has a lower thermal coefficient of expansion than soda-lime, but borosilicate glass of the same thickness is just as mechanically tough as soda-lime glass, it's just more expensive.
Pyrex kitchenware wasn’t always using soda lime glass, they changed to that from borosilicate for cost cutting reason after getting parted out in an M&A spree if I recall correctly. That’s also the reason it appears in a lot of oldschool hip hop lyrics, you gotta have the heat resistance for *that* application lol
So pyrex is basically coasting off of its name because it USED to be heat resistant. I never knew they changed it and just assumed the pyrex i have in my kitchen was resistant to heat breakage. Guess i never tested it out to know for sure lol
@@psilocybicacid7667 big issue I had once. I have some borosilicate glassware and some of the new pyrex too. And some uranium glass. (I collect weird glass I also have some cobalt glass, lead glass, and some mostly clear glass that glows blue if you turn the lights off. Don't drink out the last one though.)
@psilocybicacid7667 Pyrex makes all kinds of glassware for different purposes. Your measuring cup shouldn't be under a blow torch, so that heat shouldn't be a problem, but you likely will drop it. So making it able to not shatter into a billion razor sharp pieces is a plus. Your glass brownie pan is more heat resistant
That’s not a real test. Best I’ve found is real Pyrex “disappears” in mineral oil (same refractory) but I don’t think the Salvation Army wants me dragging a bucket of mineral oil around their store. If it’s patterned, you can use that, although some patterns have been remade
If you want borosilicate Pyrex that's new, buy it from Europe. I've heard some companies specifically import it into the US to sell at a higher margin and price. And if you want an easy way to check if modern Pyrex is borosilicate without doing the index of refraction "trick", just check where it's made. If it's made in France it's borosilicate.
The kitchen one is about 5 times thicker than the beaker. If the beaker were that thick, it'd absorb/block a lot of heat. It's assumed that people working in a lab are going to be more careful :-P
Here in continental Europe Pyrex was originally also made of borosilicate glass. But nowadays kitchen utensils of this brand are made of tempered soda lime glass - only heat resistent up to 250 degrees Celsius. In laboratory context the designation Pyrex is still synonymously used for borosilicate glassware here, as well as Duran, Supremax or Fiolax.
My mom actually is a glass blower and she uses borosilicate glass in her art! She uses a torch to melt and mold the glass into shapes and pendants! Super cool to see borosilicate glass is used in other stuff too!
I was told by a guy that made borosilicate glass pipes that you should be able to bounce it off the concrete if it's properly annealed. I'm sure that also depends on the thickness and proportions of the actual object. Obviously a 4ft bong isn't going to bounce, but a little pipe with thick boro walls might.
Pyrex used to always be borosilicate, but it switched to soda lime for consumer market because it's cheaper. The kitchen glassware is far thicker than the lab glassware which undoubtedly contributes to why it's more brittle.
Btw Back in the day Pyrex for the kitchen was ALSO borosilicate glass. They changed it to sodalime to save money and capitalize on the brand image they had from the old days
Looked to have more force on the second glass. Not only that but soda lime seems thicker than the other. We can't really tell the differences until the models are the same.
yah there is huge difference is thickness, and he didn't thermally shock the beaker, Pyrex is great to heat in even in a conventional oven, its just thermal shock will destroy most kinds of glass, i doubt the beaker would have surivived but idk
You can sometimes find old borosilicate pyrex cookware at second hand stores. It's becoming more rare though. You can tell the difference because the borosilicate stuff has the name pyrex spelt with all capital letters, and with a circle around the name.
The kitchen glassware is also 3 to 4 times thicker than the lab glass. Thicker glass will set up greater internal stresses when heated non-uniformly. The clear Pyrex kitchenware was not advertised as compatible with the stress of heating with a direct flame. Interestingly, the opaque Corning Ware (Pyroceram) was a kitchen product capable of withstanding the stresses of direct flame heating with frozen food on the inside.
Really well done video. Some people might have otherwise asked “well why not just use borosilicate glass all the time” if it weren’t for that last part of the video. Thanks!
That's because they started making soda lime. Which is "pyrex" (lowercase). The PYREX that they made for the kitchen, which was made with borosilicate, is much superior. They decided to make a cheaper inferior product and charge the same price.
Just a heads up that you can buy borosilicate glass food storage from other companies. Just because Pyrex isn't making it anymore doesn't mean you can't buy it.
Older Pyrex kitchen items were borosilicate, and it was a big selling point. They switched to soda lime in 1998 after Corning sold the brand to World Kitchen LLC. The stuff is trash now. The older stuff can sometimes be found for sale on ebay or at yard/estate sales.
Pyrex used to be synonymous with borosilicate glass. That’s all it was ever made of. You could put a Pyrex glass on a gas stove and cook with it if you wanted to, or boil water in one. At some point, Pyrex decided that they wanted to cash in on their reputation to make some extra money, and changed to regular glass which is much cheaper. If you see old Pyrex dishes at a thrift store, BUY THEM!
The older PYREX (all capital letters) Kitchenware was made out of borosilicate glass, which is more expensive to make than soda lime glass. At least in the U.S.A., pyrex (lower case letters) started to make their glassware out of soda lime glass to save money, yet still charged just as much. Be careful using the soda lime glass pyrex, I have heard of people having their glassware explode once taken out of the oven. I'm not sure if it's true, but I have heard that outside of the U.S.A. other countries would not accept the soda lime glass, and their PYREX is still borosilicate glass. Can anyone verify this?
Older pyrex bake ware was borosilicate glass. I’ve got quite a few baking dishes that are decades old. Wish they still used it. Not necessary but nice to know it’s less susceptible to cracking from thermal shock
Thats a great descriptor of the mohs scale. Diamonds are hardest substance but will shatter when hit with hammer. Where as nepherite is a mohs 6 and a hardest of 6 you can almost shatter a cheap hammer on it. Being steel is mohs sxale of 3
It's because of micro imperfections in the glass that are continually strained and made worse by the heating and cooling process. Heating makes it expand ever so slightly and then cooling shrinks it
It depends a lot, the hardening and strengthning techniques they use on cooking wear is a lot different then what they do with lab glass because they assume people using lab glass wear are going to be a bit more careful.
Gotta double check if it's pyrex or PYREX. The capital vs lower case is a good identifier for what material it's using. Cookware can be found that's made of borosilicate glass (PYREX), but is not as common as soda lime (pyrex).
soda glass is also much cheaper, I buy all my pyrex vintage or specifically known borosilicate versions. They are more fragile but I don't have to worry about them exploding in the microwave.
Pyrex used to exist entirely for the purpose of being a recognizable brand of borosilicate glass. Soda-lime Pyrex is the Pyrex company trying to scam us.
You can still get the good stuff. Just make sure it's PYREX and not Pyrex or pyrex.
It used to be borosilicate they one day stopped using it to make more profits. My dad still has a old bake dish and when he makes roasts he will put it on a gas burner and make gravy never once had a shatter can't say the same for modern glass ware from them
Iirc it caused problems for meth cooks when they made the switch.
Someone already said it. Gotta look for the all caps
The good stuff is yellowish. The blue-green stuff is maybe aluminosilicate, maybe just glass.
Slightly taps kitchen pyrex glass
SMACKS science pyrex glass
Plus heated the Pyrex kitchen up with consistent heat and on the pyrex beaker he was moving the heat back and forth therefore the heat was more focused on the kitchen and not as much on the beaker if he would have kept the heat as consistent the beaker would have done the same as kitchen pyrex
The lab product was also thinner than the kitchen measuring cup. I NEVER had a PYREX (borosilicate glass) shatter. It definitely has been put under mechanical stress also.
Exactly
Turbo flex vs normal glass
@@willzander6514 cool. Pray that your glass continues workin then? Idk what you want from the dude. He tested them. 1 sucks the other doesn’t. And just cause it turns out to be the “good Pyrex” doesn’t mean it can’t shatter from heat 😂
I think the rule is PYREX, then Pyrex then pyrex.
The all lowercase pyrex is much weaker than PYREX
Interesting....
According to Wikipedia, it's a mish-mash.
en.m.wikipedia.org/wiki/Pyrex
@@tgeliot great link. Thank you
European PYREX is still made from borosilicate glass.
I have my mother’s PYREX glassware, it’s about eighty years old and it’s brilliant.
@@tgeliot From the same article: “Since the closure of the soda-lime plant in England in 2007, European Pyrex has been made solely from borosilicate.”
This is why old Pyrex dishware is valued so highly; all Pyrex used to be made of borosilicate until they swapped the kitchenware to cheaper soda lime glass.
It's not that valuable. You can just buy it new from Europe (and I'm sure many other places) where it's still made with borosilicate.
If you want an easy way to tell if modern Pyrex is borosilicate, check where it's made. If it's made in France it'll be borosilicate.
@@lost4468yt "valued" and "valuable" are two different concepts imo. they made an entire show on this contrasting premise via "pawn stars".
plenty of folks brought in highly valued family heirlooms that simply weren't worth much of anything other than a "great" tv moment, a very questionable value if you ask me lol.
No the DEA encouraged them to change to soda lime
@@jn1211 so does this same concept follow old barn wood? Regular wood goes for about $8 for 2x4s in my area, whereas “vintage” barn wood can sell for double or triple that.
Pyrex in the Uk still uses borosilicate. Only you guys in the US get the cheap stuff. 😂
Another note to take, Is that the *borosilicate glass beaker* is much much *thinner glass* , this is because if your glass is thicker the *Heat from your blow torch will travel on the outside of the glass* (because it thick) and the *inner wall of the glass will be at a different temp*, this causes *uneven expansion* and that can *crack/shatter the glass*, that’s way lab glass is generally thin.
Very good answer.
Username checks out
This makes a lot of sense, I had not really considered why most common glassware is fairly thin.
Expanding on this all the thicker glassware that I've ever seen in a lab are those that are typically used under vacuum (negitive pressure).
They also hit the beaker harder
My PYREX cookware (upper case PYREX is borosilicate) is as thick as the pyrex (lower case pyrex is soda-lime) you got over in the states.
It’s also worth noting there are two different companies selling glassware under the name “Pyrex”. The PYREX brand is borosilicate. The pyrex brand is soda lime
I like how consistent your pressure was in each swing of that hammer. Really consistent to make the test more accurate
It was scary how accurately both sets of swings were exactly the same.
@@mikej9470 Frightening
Thickness of the glass is also a huge factor, thermal expansion of glass is the issue causing the shattering, borosilicate has a lower thermal coefficient of expansion than soda-lime, but borosilicate glass of the same thickness is just as mechanically tough as soda-lime glass, it's just more expensive.
Funny that he didn't realize that one was thicker than the other when smashing the hammer onto it.
Pyrex kitchenware wasn’t always using soda lime glass, they changed to that from borosilicate for cost cutting reason after getting parted out in an M&A spree if I recall correctly. That’s also the reason it appears in a lot of oldschool hip hop lyrics, you gotta have the heat resistance for *that* application lol
THAT LITERALLY KILLS THE ENTIRE POINT WTF
So pyrex is basically coasting off of its name because it USED to be heat resistant. I never knew they changed it and just assumed the pyrex i have in my kitchen was resistant to heat breakage. Guess i never tested it out to know for sure lol
@@psilocybicacid7667 big issue I had once. I have some borosilicate glassware and some of the new pyrex too. And some uranium glass. (I collect weird glass I also have some cobalt glass, lead glass, and some mostly clear glass that glows blue if you turn the lights off. Don't drink out the last one though.)
@@psilocybicacid7667 you know whats even funnier, European Pyrex is still out of borosilicate
@psilocybicacid7667 Pyrex makes all kinds of glassware for different purposes. Your measuring cup shouldn't be under a blow torch, so that heat shouldn't be a problem, but you likely will drop it. So making it able to not shatter into a billion razor sharp pieces is a plus. Your glass brownie pan is more heat resistant
I like how gently you hit the kitchen measuring cup, then whacked the SHIT out of the lab glass. 🤣
There was a time when the Pyrex brand was legit.
You need to look for PYREX and not the pyrex
In most countries Pyrex is still borosilcate glass.
@@pvstlife4028 in some countries (like USA), Pyrex is actually toughened soda-lime glass, bit borosilcate.
I think in Canada it's still borosilicate but everything comes from China now so most likely not
I love this demonstration! It's really interesting to see the difference.
Thank you
Yeah, really. The comments are good too. I was sure that Pyrex always meant borosilicate, but apparently it was changed due to cost savings..
He struck the lab glass considerably harder than the kitchen glass with that hammer. I want a reshoot
It actually just depends if you get the really PYREX and not the knockoff pyrex.
Always look for the uppercase (it’s rare)
That’s not a real test.
Best I’ve found is real Pyrex “disappears” in mineral oil (same refractory) but I don’t think the Salvation Army wants me dragging a bucket of mineral oil around their store.
If it’s patterned, you can use that, although some patterns have been remade
It‘s being held by metal. The glass and metal are heated and cooled at different temperatures
my argument when someone uses the nerd emoji:
I'm 💯% 🤓
If you want borosilicate Pyrex that's new, buy it from Europe. I've heard some companies specifically import it into the US to sell at a higher margin and price.
And if you want an easy way to check if modern Pyrex is borosilicate without doing the index of refraction "trick", just check where it's made. If it's made in France it's borosilicate.
The kitchen one is about 5 times thicker than the beaker. If the beaker were that thick, it'd absorb/block a lot of heat. It's assumed that people working in a lab are going to be more careful :-P
Here in continental Europe Pyrex was originally also made of borosilicate glass.
But nowadays kitchen utensils of this brand are made of tempered soda lime glass - only heat resistent up to 250 degrees Celsius.
In laboratory context the designation Pyrex is still synonymously used for borosilicate glassware here, as well as Duran, Supremax or Fiolax.
I don't know about continental Europe but in the UK Pyrex is still borosilicate glass.
I know about continental Europe and it is still made of borosilicate glass.
I had this issue with a other brand glas jar. After trying destillation, it broke. I now stick to borosilicate
I'm almost certain that Pyrex cookware used to be made of borosilicate, as I remember them swapping it out some time ago for salt lime
Your channel is so under rated Tommy! Love your work 😊
Wow, thank you 😊😊😊
My mom actually is a glass blower and she uses borosilicate glass in her art! She uses a torch to melt and mold the glass into shapes and pendants! Super cool to see borosilicate glass is used in other stuff too!
Probably not the same kind of glass exactly as in the video so please don't try and melt a random cup it won't go well
This 19 mm boro pipe from Colorado was thrown across the smoke shop, and then I bought it.
Thank you for explaining my friend. I always wondered why Pyrex scientific glass was different.
Hits them both with different amounts of force
This is your glass, "VIOLENTLY SMASH"
this is turboflex glass, "gentle nudge"
pyrex shards are very sharp !
Indeed
My mother had bowls made of the same stuff of pyrex, they bounced on the kitchen floor like a basketball and I don't think they even chipped.
Old Pyrex is tough af
I was told by a guy that made borosilicate glass pipes that you should be able to bounce it off the concrete if it's properly annealed. I'm sure that also depends on the thickness and proportions of the actual object. Obviously a 4ft bong isn't going to bounce, but a little pipe with thick boro walls might.
Thats why I buy old pyrex stuff from goodwill. The old studf was actual borosilicate glass.
Pyrex used to always be borosilicate, but it switched to soda lime for consumer market because it's cheaper. The kitchen glassware is far thicker than the lab glassware which undoubtedly contributes to why it's more brittle.
I grew up in the 80's and I didn't know Pyrex had stopped being borosilicate. We had a saucepan made of the stuff.
You hit that borosilicate glass a lot harder lol
“Man I love some good ole Pyrex shrapnel”
~Ronnie “Reaganomics” Reagan
Really?
*When meth heads used to get tubes of Pyrex to blow bowls*
I remember those days
*Another Turboflex moment*
The magic 🪄 of Chemistry in the mix
Btw
Back in the day Pyrex for the kitchen was ALSO borosilicate glass.
They changed it to sodalime to save money and capitalize on the brand image they had from the old days
Lol. I love the end, with the gentle, cautious taps on the jar vs the heavy strikes of someone with a genuine desire to smash the beaker 😂
I once dropped a pyrex measuring cup and it completely shattered. Still to this day the most impressive thing I've ever done
your glassware. Turboflex glassware
Naturally, if put direct flame on one, and indirect flame on the other. 🤦♂️
you hit it way harder
Pyrex also makes quartz glass which is the glass that gives high frequency pitch when rubbed.
Interesting...I didn't know this
@@TommyTechnetium now I have taught you something. 😊
@@TheDeepDiveLLC I love it!
So let’s mix them together and make a undisputed champion
Not even gonna lie, those hits looked like some "your glasses/turboflex glasses" hits
I'm loving this channel!!!
Thank you 😊
You hit it harder though
(hits it WAY harder) "ya it doesn't hold up so well" 😂
Looked to have more force on the second glass. Not only that but soda lime seems thicker than the other. We can't really tell the differences until the models are the same.
yah there is huge difference is thickness, and he didn't thermally shock the beaker, Pyrex is great to heat in even in a conventional oven, its just thermal shock will destroy most kinds of glass, i doubt the beaker would have surivived but idk
You can sometimes find old borosilicate pyrex cookware at second hand stores. It's becoming more rare though. You can tell the difference because the borosilicate stuff has the name pyrex spelt with all capital letters, and with a circle around the name.
Example: (PYREX)
I really appreciate your explanation. TY👍🏽
😊
That laboratory beaker at the end still had a hint of green to it.
Bro did turboflex demonstration with laboratory glass
The kitchen glassware is also 3 to 4 times thicker than the lab glass. Thicker glass will set up greater internal stresses when heated non-uniformly. The clear Pyrex kitchenware was not advertised as compatible with the stress of heating with a direct flame. Interestingly, the opaque Corning Ware (Pyroceram) was a kitchen product capable of withstanding the stresses of direct flame heating with frozen food on the inside.
I agree, glass cookware that explodes when heated sounds like something that should absolutely be used in the kitchen
😂
Really well done video. Some people might have otherwise asked “well why not just use borosilicate glass all the time” if it weren’t for that last part of the video. Thanks!
the last part got me like:
"your glassware vs, turboflex glassware"
This is a volumetric flask Jessie, you don't cook in a volumetric flask.
This wins a Tommy Technetium bronze comment award 🥉
Bro hit the kitchen glass lighter. His wife in the background with a knife checking out if he gonna break her shit 🤣
😂😂
That's because they started making soda lime. Which is "pyrex" (lowercase). The PYREX that they made for the kitchen, which was made with borosilicate, is much superior. They decided to make a cheaper inferior product and charge the same price.
Metal ring and borosilicate glass expand/compress at different rates. Put the measuring cup on a ceramic plate then heat it and it will not shatter
I've done this. Indeed it shatters. See also www.chemedx.org/blog/pyrex-any-other-name
@@TommyTechnetium I did not know household Pyrex was different than lab equipment Pyrex until your video too!
Good to know! We have the Pyrex measuring cup and it's my favorite.
Just a heads up that you can buy borosilicate glass food storage from other companies. Just because Pyrex isn't making it anymore doesn't mean you can't buy it.
Both the thermal shattering and the breakage resistance are partly because the kitchen pyrex is thicker.
Older Pyrex kitchen items were borosilicate, and it was a big selling point. They switched to soda lime in 1998 after Corning sold the brand to World Kitchen LLC. The stuff is trash now. The older stuff can sometimes be found for sale on ebay or at yard/estate sales.
Very good lesson.
Pyrex used to be synonymous with borosilicate glass. That’s all it was ever made of. You could put a Pyrex glass on a gas stove and cook with it if you wanted to, or boil water in one. At some point, Pyrex decided that they wanted to cash in on their reputation to make some extra money, and changed to regular glass which is much cheaper.
If you see old Pyrex dishes at a thrift store, BUY THEM!
Or buy your PYREX outside of the USA - European PYREX is still made with borosilicate glass!
bro smacked the second one with some anger
Dude just love tapped the kitchen one and hulk hoganed the second one
Thanks for the explanation.. I recently experienced this : )
You need the uppercase PYREX glassware its better
The older PYREX (all capital letters) Kitchenware was made out of borosilicate glass, which is more expensive to make than soda lime glass. At least in the U.S.A., pyrex (lower case letters) started to make their glassware out of soda lime glass to save money, yet still charged just as much.
Be careful using the soda lime glass pyrex, I have heard of people having their glassware explode once taken out of the oven.
I'm not sure if it's true, but I have heard that outside of the U.S.A. other countries would not accept the soda lime glass, and their PYREX is still borosilicate glass.
Can anyone verify this?
Thanks for the clarification.
Older pyrex bake ware was borosilicate glass. I’ve got quite a few baking dishes that are decades old. Wish they still used it. Not necessary but nice to know it’s less susceptible to cracking from thermal shock
Two different brands - PYREX and pyrex
Just read about it.
Pyrex - Wikipedia
I learned something new today. Thank you. I'll never use this info but it was cool to find out.
Thanks for the heads-up
My beaker:☁️🛏️
Your beaker:💣🧱
It's mostly because of thickness. Laboratory glass can also be from usual materials.
The fact it took the first hit was impressive
bro clearly hit them differently
Bro, that just gave me some real turbo flex vibes
Thats a great descriptor of the mohs scale. Diamonds are hardest substance but will shatter when hit with hammer. Where as nepherite is a mohs 6 and a hardest of 6 you can almost shatter a cheap hammer on it. Being steel is mohs sxale of 3
Pulling the old turboflex on us, lmao
Okay you definitely hit the beaker harder lmao
Now if we could just make something that has the properties of both.... Thick walled boro glass! But damn is it expensive!!!!
For note pyrex used to be borosilicate glass. If memory serves the switch was in the 80's
It's because of micro imperfections in the glass that are continually strained and made worse by the heating and cooling process. Heating makes it expand ever so slightly and then cooling shrinks it
It depends a lot, the hardening and strengthning techniques they use on cooking wear is a lot different then what they do with lab glass because they assume people using lab glass wear are going to be a bit more careful.
Bro pulled a turboflex
Naturally, if you hit one harder than the other. 🤦♂️
Breakers are also much thinner than a measuring cup so they flex better and that's why they're less resistant to mechanical stress...
Difference in PYREX and pyrex
Bro did the turboflex
Gotta double check if it's pyrex or PYREX. The capital vs lower case is a good identifier for what material it's using. Cookware can be found that's made of borosilicate glass (PYREX), but is not as common as soda lime (pyrex).
English Pyrex is borosilicate
soda glass is also much cheaper, I buy all my pyrex vintage or specifically known borosilicate versions. They are more fragile but I don't have to worry about them exploding in the microwave.
Notice how the one is almost 4 times the thickness...
Kitchen glass: *tap tap tap with hammer*
Lab glass: *Beats harder than my step dad beats me"
Hua that's actually really cool to know. I've grown up around a lot of clandestine chemists and I've always assumed all pyrex was the same