Designers and manufacturers of diaphragm chucks have in the past been limited to the use of empirical data for diaphragm chuck design. This limitation has been due to the complex nature of mathematically analysing the chuck. This work established, by theory and experimental verification, the prediction equation for the gripping force of a diaphragm chuck for any number of jaws. The designer is therefore able to achieve aprioridesign of the diaphragm chuck.