A retort stand, sometimes called a clamp stand or a ring stand, is a piece of scientific equipment to which clamps can be attached to hold other pieces of equipment and glassware – for instance, burettes, test tubes and flasks. Accessories such as ring clamps, versatile clamps, 3-prong clamps, and burette clamps can be attached to better hold certain types of glassware.. The basic retort stand consists of two main metal pieces: the base and the retort rod.
Retort stands commonly have a cast iron base of around 200 x 125 mm. The rod may be up to 750 mm and screws into a female thread in the base. The height of the rod is sufficient for most experiments and usually fits within fume hoods and glove boxes. If a taller rod is required, the solid base is usually replaced by a tripod for stability when supporting larger apparatuses, such as extremely large tubes, bulk chemical bottles etc. The height can be adjusted by moving the attached point of the stand and the test tube. The base lowers centre of gravity of the stand, thus increasing stability.
Retort stands are often used in the chemistry laboratory. For instance, they are used for distillation experiments (such as organic distillations) and titrations (where they hold a burette). They are also used as supports in filtration.