Flowdrilling: a Preliminary Analysis of a New Bush-Making Operation

Flowdrilling is a bush-making operation applied to thin walled products for joint engagement. Fastenings exhibit mechanical properties which depend largely on the shear strength of the parent material and the area of engagement. Flowdrilling is specifically designed to increase the latter. Developments during the last six or seven years have resulted in a number of industrial usefull applications. Previous attempts to use “rotary plunging methods” failed due to low tool life and the inability to obtain an acceptable finish. The paper describes the different process variables and gives the results of a preliminary analysis of the different mechanical and physical aspects. Manufacturing properties like cycle time and tool life are also dealt with.