Test tubes and boiling tubes

There can't be many students who cannot recognize a test tube. These pieces of glassware are used to carry out chemical tests and small scale reactions. The difference between them is their diameter. A boiling tube is wider than a test tube. This makes it better suited for boiling liquids in, as they are less likely to bump. However, this dangerous behaviour still does occur, so care needs to be taken when boiling a liquid.

Test tubes and boiling tubes can be made of cheap soda glass or more expensive borosilicate (hard) glass. The latter type should be used for strong heating as soda glass melts quite easily. Prolonged strong heating in a Bunsen flame will also melt borosilicate glass, so care still needs to be taken.