Cork is a natural product by any definition but one doesn’t normally associate it with lab equipment. Its remarkable properties make it a useful material when working with things that are very hot,  very cold or readily broken.

Properties of Cork

Cork is elastic,  resilient, lightweight, a good insulator, impermeable, durable and hypoallergenic. You can squeeze it into small spaces & it will form a tight seal. It doesn’t absorb water based liquids and is a poor heat conductor(1).
Cork surface showing cellss

Cork cells are 14 sided polyhedrons which are highly compressible and elastic. They are ideal for stoppering bottles, test tubes and flasks and course as underflooring.

 Uses of Cork

These properties make cork a good gasket material, excellent badminton shuttlecocks, superb acoustic and thermal insulators in walls, floors and ceilings durable bulletin boards(2).

The most familiar use is of course as a stopper for wine bottles but they will keep air out of flasks and test tubes to prevent contamination and evaporation as well.  It’s also hypoallergenic which makes it good for storing food and drink.

We offer a variety of cork stopper and glassware combinations including test tubes, Erlenmeyer flasks and boiling flasks. They make attractive and economical containers for product display in businesses and food and beverage storage at home or work.

Cork stoppers

Cork stoppers have a tapered shape for easy insertion and removal.

Cork is also a good insulator and conducts heat very poorly. This makes it a good material to line clamps that are used to support test tubes and flasks that need to be heated. In addition to this, its compressibility allows the 4 fingers of the clamp to be tightened to secure the glassware without risk of breaking it.

cork lined 4 finger clamps

Cork lined 4 finger clamps resist both heat and compression which makes them superior tools for holding glassware such as test tubes and flasks.

Cork is works well with very cold things.  Dewars, basically big thermos bottles, are used to store liquid nitrogen and capped with cork stoppers to keep heat out.

You can also use them for holding very sharp items such as insect pins. Just stick them into an inverted stopper & use when needed.


1) The amazing natural properties of cork.

2) Cork (material) – Wikipedia

3) Cork: properties, capabilities and applications. This 21 page paper covers everything from microscopy to chemistry to physical properties.

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