Conical flask with thread and polypropylene cap

Threaded Flasks/conical-flask-with-a-narrow-throat">Conical Flasks with Secure Polypropylene Sealing Systems

You know those moments when you're preparing a solution and need to shake it vigorously without worrying about spills? That's exactly where these threaded conical flasks shine. The precision-molded threads on the neck create a tight seal with the polypropylene cap, so you can actually invert the flask without that nervous feeling you get with regular stoppers.

I've been using these for years, and honestly, they've saved me from countless cleanup disasters. The borosilicate glass construction handles thermal shock like a champ - you can go from hot plate to cold water bath without that heart-stopping crack sound. The conical shape does what it's supposed to: creates those nice vortexes when you're mixing, and everything flows smoothly when pouring.

Thread Compatibility and Cap Design Features

The threading system here is pretty straightforward but effective. GL-45 threads are standard on most sizes, which means you're not stuck hunting for proprietary caps. The polypropylene caps come with inner threading that grips firmly - you'll feel about three full rotations before it's hand-tight.

If you're comparing these to a Conical flask with grind, the threaded version wins for everyday use. Ground glass joints are great for connecting to Condensers or a Straight tube condenser during reflux setups, but for storage and general prep work, threads are more practical. You can tighten them one-handed while holding a pipette in the other.

Leak-Proof Storage Applications

• Volatile solvents: Ethanol, acetone, and chloroform stay put even during transport between benches
• Culture media: Keeps sterility intact better than cotton plugs or foil caps
• Sample archiving: Stack them in the fridge without cross-contamination worries
• Mobile work: Taking samples to another building? These won't leak in your transport box

Unlike Laboratory glasses and beakers which need separate covers, the integrated cap system here means one less thing to track down. I've also found these more reliable than a Conical flask with a narrow throat when you need to add reagents through the opening while maintaining some vapor containment.

Chemical Resistance Properties

The borosilicate glass handles pretty much everything you'll throw at it - acids, bases, organics. The polypropylene caps resist most common lab chemicals too, though avoid prolonged contact with strong oxidizers or aromatics above 60°C. I learned that one the hard way with hot toluene.

Autoclavable up to 121°C with the cap loosened, these work great for media prep. Just remember to let them cool before tightening - thermal expansion is real, and you don't want to crack the threads.