Stirring Rods

Stirring rods are usually made of borosilicate glass and are similar in style to drinking straws. There are various lengths but are usually ten to forty centimetres long and half a centimetre thick. They are made from single lengths of thin glass which are cut into segments. After manufacture, they are flame polished which gives them their characteristic round ends. Apart from different lengths, there is not a great deal of variety in stirring rods although they may have paddle or plain ends. Like other pieces of laboratory glassware, they can be sterilised and as yet, they have not been replaced by other materials. Stirring rods are found in most laboratories as they are extremely versatile. They can be used for mixing and provide controlled agitation without interacting with the chemicals directly. When working with potentially hazardous chemicals, these tools allow the mixture to be poured slowly to avoid too rapid a chemical reaction. When decanting supernatants, the contact of the rod helps negate the adhesion to the side of glassware without agitating the solid. To induce crystallisation, the rod is scrapped against the inside of the flask containing the solution. The stirring rod can break up emulsion during extraction.