Fuel tight fastening by automatic machine

CONTROLLED EXPANSION has an important implication in the mechanical fastening of high performance structures. The technique provides that a cylindrical fastener expands plastically during installation to a slightly hour glass shaped cross section. Expansion is one to two per cent of the hole diameter at the shear plane, and three to five per cent at the surfaces. The result is a joint with remarkable integrity and attractive in cost saving potential. The advantages of controlled expansion are being incorporated into the fastening of the A300B wing structure after a critically thorough study of the systems described herein, in comparison with all proven and potential alternatives.